SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement contains forward-looking statements, including statements based upon or relating to our expectations, assumptions, estimates, and projections. In some cases, you can identify forward-looking statements by terms such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “anticipate,” “estimate,” “predict,” “potential,” “plan” or the negative of these terms, and similar expressions. These statements are not guarantees of future performance; they reflect our current views with respect to future events and are based on assumptions and estimates and subject to known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be Heldmaterially different from expectations or results projected or implied by forward-looking statements. These risks include, but are notlimited to:

•the severity, magnitude, and duration of the novel coronavirus pandemic, including impacts of the pandemic and of responses to the pandemic by governments, business and individuals on May 15, 2019:our operations, personnel, buyers, sellers, and on the global economy and theadvertising marketplace;

•our ability to successfully integrate the Telaria business and realize the anticipated benefits ofthe merger;

The company’s 2019 Proxy Statement•our ability to grow and to manage ourgrowth effectively;

•our ability to develop innovative new technologies and remain amarket leader;

•our ability to attract and retain buyers and sellers of digital advertising inventory, or publishers, and increase our businesswith them;

•our vulnerability to loss of, or reduction in spendingby, buyers;

•our reliance on large sources of advertising demand, including demand side platforms (“DSPs”) that may have or develop high-risk credit profiles or fail to pay invoices when due, including as a result of lower ad spending generally and/or general liquidity constraints experienced by buyers resulting from the novelcoronavirus pandemic;

•our ability to maintain and grow a supply of advertising inventory from sellers and to fill theincreased inventory;

•the effect on the advertising market and our business from difficult economic conditionsor uncertainty;

•the freedom of buyers and sellers to direct their spending and inventory to competing sources of inventoryand demand;

•our ability to cause buyers and sellers to use our solution to purchase and sell higher value advertising and to expand the use of our solution by buyers and sellers utilizing evolving digital media platforms,including CTV;

•our reliance on large aggregators of advertising inventory, and the concentration of CTV among a small number of large publishers that enjoy significantnegotiating leverage;

•our ability to introduce new offerings and bring them to market in a timely manner, and otherwise adapt in response to client demands and industry trends, including shifts in linear TV to CTV, digital advertising shift from desktop to mobile channels and other platforms and from display to video formats and the introduction and market acceptance of Demand Manager;

•uncertainty of our estimates and expectations associated with new offerings, including CTV, header bidding, private marketplace, mobile, video, Demand Manager, andtraffic shaping;

•the possibility of lower take rates and the need to grow through increasing the volume and/or value of transactions on our platform and increasing ourfill rate;

•our vulnerability to the depletion of our cash resources as a result of the adverse impacts of the novel coronavirus pandemic, or as we incur additional investments in technology required to support the increased volume of transactions on our exchange and to developnew offerings;

•our ability to support our growth objectives with reduced resources from our costreduction initiatives;

•our ability to raise additional capital if needed and/or renew our working capital lineof credit;

•our limited operating history and historyof losses;

•our ability to continue to expand into new geographic markets and grow our market share inexisting markets;

•our ability to adapt effectively to shifts indigital advertising;

•increased prevalence of ad-blocking or cookie-blocking technologies and the slow adoption ofcommon identifiers;

•the slowing growth rate of desktopdisplay advertising;

•the growing percentage of online and mobile advertising spending captured by owned and operated sites (such as Facebook, Google,and Amazon);

•industry growth rates for ad-supported CTV and the shift in video consumption from linear TV to digital mediums such as CTV and over-the-top ("OTT");

•the adoption of programmatic advertising byCTV publishers;

•the effects, including loss of market share, of increased competition in our market and increasing concentration of advertising spending, including mobile spending, in a small number of verylarge competitors;

•the effects of consolidation in the adtech industry;

•acts of competitors and other third parties that can adversely affectour business;

•our ability to differentiate our offerings and compete effectively in a market trending increasingly toward commodification, transparency,and disintermediation;

•requests for discounts, fee concessions or revisions, rebates, refunds, favorable payment terms and greater levels of pricing transparencyand specificity;

•our ability to ensure a high level of brand safety for our clients and to detect “bot” traffic and other fraudulent ormalicious activity;

•the effects of seasonal trends on our resultsof operations;

•costs associated with defending intellectual property infringement andother claims;

•our ability to attract and retain qualified employees andkey personnel;

•political uncertainty and the ability of the company to attract politicaladvertising spend;

•our ability to identify future acquisitions of or investments in complementary companies or technologies and our ability to consummate the acquisitions and integrate such companies ortechnologies; and

•our ability to comply with, and the effect on our business of, evolving legal standards and regulations, particularly concerning data protection and consumer privacy and evolvinglabor standards.

We discuss many of these risks and additional factors that could cause actual results to differ materially from those anticipated by our forward-looking statements under the headings "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operations," and elsewhere in filings we have made and will make from time to time with the Securities and Exchange Commission, or SEC, including our Annual Report on Form 10-K for the fiscal year ended December 31, 20182019 and subsequent Quarterly Reports on Form 10-Q for 2020, including our Form 10-Q for the three months ended March 31, 2020. These forward-looking statements represent our estimates and assumptions only as of the date of the report in which they are availableincluded. Unless required by federal securities laws, we assume no obligation to update any of these forward-looking statements, or to update the reasons actual results could differ materially from those anticipated, to reflect circumstances or events that occur after the statements are made. Without limiting the foregoing, any guidance we may provide will generally be given only in connection with quarterly and annual earnings announcements, without interim updates, and we may appear at http://www.astproxyportal.com/ast/18899.industry conferences or make other public statements without disclosing material nonpublic information in our possession. Given these uncertainties, investors should not place undue reliance on these forward-looking statements.

Investors should read this proxy statement and the documents that we reference in this report and have filed or will file with the SEC completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of our forward-looking statements by these cautionary statements.

The Rubicon Project, Inc.
12181 Bluff Creek Drive, 4th Floor
Los Angeles, California 90094

PROXY STATEMENT FOR THE ANNUAL MEETING OF STOCKHOLDERS
TO BE HELD ON MAY 15, 2019JULY 8, 2020

This proxy statement is provided in connection with the solicitation of proxies by the board of directors (the “board of directors” or “board”) of The Rubicon Project, Inc. (the “company” or “Rubicon Project”) for use at the Rubicon Project annual meeting of stockholders to be held at the company’s principal executive offices, located at 12181 Bluff Creek Drive, 4th Floor, Los Angeles, California 90094, on Wednesday, May 15, 2019July 8, 2020 at 12:00 noon localPacific time, and at any postponement or adjournment thereof (the “Annual Meeting”).In light of the coronavirus (COVID-19) pandemic and the protocols that federal, state and local governments are currently imposing, and out of an abundance of caution and appreciation for our stockholders,the Annual Meeting will be a virtual meeting via live webcast on the Internet. You will be able to attend the Annual Meeting, vote and submit your questions during the meeting by visitinghttps://web.lumiagm.com/293659257 and entering the control number included in the Notice of Internet Availability or the proxy card or voting instruction form (if you received a printed copy of the proxy materials) that you receive. You will not be able to attend the annual meetingin person.

IMPORTANT NOTICE REGARDING INTERNET AVAILABILITY OF PROXY MATERIALS

This proxy statement and our Annual Report on Form 10-K for the year ended December 31, 2019 (the “2019 Annual Report”) are available on the Internet at www.proxyvote.com.  These materials are also available on our corporate website at http://investor.rubiconproject.com/. The other information on our corporate website does not constitute part of thisproxy statement.

GENERAL INFORMATION ABOUT THE ANNUAL MEETING

You are invited to attend the Annual Meeting via live webcast, and we request that you vote on the proposals described in this proxy statement.statement as soon as possible. You can vote your shares without attending the Annual Meeting by appointing a proxy to vote your shares as explained below. Pleasebelow.Please note that if your shares are held of record by a broker, bank or other nominee and you decide to attend and vote at the Annual Meeting in person, your vote in person at the Annual Meeting will not be effective unless you present a legal proxy, issued in your name from your broker, bank or otherorother nominee.

Notice of Internet Availability of Proxy Materials

In accordance with rules and regulations adopted by the Securities and Exchange Commission (the “SEC”), instead of mailing a printed copy of our proxy materials, we are furnishing proxy materials to our stockholders on the Internet and mailing printed copies of the proxy materials only to a limited number of our stockholders. If you are a stockholder of record and you have received a printed copy of these proxy materials by mail, you may simply complete, sign and return your proxy card by mail or follow the instructions on your proxy card to submit your proxy via the Internet or telephone. If you hold your shares in street name, which means your shares are held of record by a broker, bank, or other nominee, you will receive instructions from your broker, bank, or other nominee on how to vote your shares. Stockholders receiving a Notice of Internet Availability of Proxy Materials by mail will generally not receive a printed copy of the proxy materials unless they specifically request a printed copy in accordance with the instructions included in the Notice of Internet Availability of Proxy Materials. The Notice of Internet Availability of Proxy Materials provides instructions as to how to (i) access and review the information contained in the proxy materials, (ii) submit voting instructions via the Internet or telephone or by mail, and (iii) request a printed copy of the proxy materials. You may also participate in and vote at the Annual Meeting by visiting the following website:https://web.lumiagm.com/293659257. See “Matters Related to Virtual Annual Meeting” below for further instructions.Even if you plan to participate in the Annual Meeting, we recommend that you submit your proxy or voting instructions in advance to authorize the voting of your shares at the Annual Meeting so that your vote will be counted if you later are unable to attend theAnnual Meeting.

We intend to begin distributing our proxy materials to stockholders via paper copy mailing and the Notice of Internet Availability of Proxy Materials on or about April 5, 2019.May27, 2020.

Business to be Conducted at Annual Meeting; Recommendation of Board of Directors

Each properly submitted proxy will be voted in accordance with the stockholder’s instructions contained therein. If no choice is specified, properly executed proxies that have not been revoked will be voted in accordance with the recommendations of the board of directors:directorsas follows:

•FOR election of each of the Class III directors to serve until the company’s 2023 annual meeting of stockholders and until their respective successors are duly elected and qualified (see “Proposal 1 – Electionof Directors”);

•FOR ratification of theselection of Deloitte & Touche LLP as the company’s independent registered public accounting firm for the current fiscal year (see “Proposal 2 – Ratification of the Selection of Deloitte & Touche LLP as Independent Registered PublicAccounting Firm”);

•FOR approval, on an advisory basis, of the compensation of the company’s named executive officers (see “Proposal 3 —Advisory Vote to Approve the Compensation of our Named ExecutiveOfficers”); and

•1 YEAR as the frequency of future advisory votes on the compensation of the company’s named executive officers (see “Proposal 4 — Advisory Vote on the Frequency of Future Advisory Votes on the Compensation of our NamedExecutive Officers”).

As to any other business that may properly come before the Annual Meeting, the persons acting as proxies will vote, or otherwise act, in accordance with their judgment on such matter. Our board of directors does not presently know of any other business that may come before the AnnualtheAnnual Meeting.

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The company will pay all costs of proxy solicitation. In addition to solicitations by mail, our directors, officers and employees, without additional remuneration, may solicit proxies by telephone, facsimile and personal interviews, and we reserve the right to retain outside agencies for the purpose of soliciting proxies. Brokers, custodians, and fiduciaries will be requested to forward proxy soliciting materials to the owners of stock held in their names and, as required by law, we will reimburse them for their out-of-pocket expenses in thisinthis regard.

Matters Relating to Virtual Annual Meeting

Our board of directors annually considers the appropriate format of our annual meeting of stockholders. As part of our effort to maintain a safe and healthy environment for our directors, members of management and stockholders who wish to attend the Annual Meeting, and in light of the novel coronavirus disease, COVID-19, our board of directors believes that hosting a virtual Annual Meeting is in our best interest and the best interest of our stockholders and enables increased stockholder attendance and participation during a time when many travel restrictions are in place and may limit attendance at our Annual Meeting. Furthermore, our board of directors has determined that hosting a virtual annual meeting of stockholders will provide expanded access, improved communication, and cost savings. Hosting a virtual meeting enables increased stockholder attendance and participation since stockholders can participate from any location around the world. We intend that the virtual meeting format will provide stockholders a similar level of transparency to the traditional in-person meeting format and we take steps to ensure such an experience. Our stockholders will be afforded the same opportunities to participate at the virtual Annual Meeting as they would at an in-person annual meetingof stockholders.

The live audio webcast of the Annual Meeting will begin promptly at 12:00 noon Pacific time. Online access to the audio webcast will open 15 minutes prior to the start of the Annual Meeting to allow time for you to login and test your internet-connected device’s audio system. We encourage you to access the meeting in advance of the designated time. We will have technicians ready to assist you with any technical difficulties you may have accessing the virtual meeting or submitting questions. If you encounter any difficulties accessing the virtual meeting during the check-in or meeting time, please call the technical support number that will be posted on the virtual meeting login page.

If you want to participate in and vote at the Annual Meeting, you will need will need the control number included on your Notice of Internet Availability of Proxy Materials or your proxy card or voting instruction form (if you received a printed copy of the proxy materials) or included in the email to you if you received the proxy materials by email in order to be able to vote your shares or submit questions during theAnnual Meeting. 

In addition, if you hold your shares in “street name” through an intermediary, such as a bank, broker or other nominee, in order to participate in and vote at the Annual Meeting you must first obtain, in advance, fromyour bank, broker or other nominee, a legal proxy reflecting the number of shares of the Company’s common stock that you held as of the record date, your name and email address, unless you previously obtained a legal proxy from your bank, broker or other nominee. You must then submit a request for registration toAST by email toproxy@astfinancial.com. Requests for registration must be labeled as “Legal Proxy” and be received byAST no later than 5:00 p.m. Eastern Time onJune 30, 2020. Obtaining a legal proxy may take several days, or longer, and stockholders are advised to register as far in advance as possible. Proxy holders registered withAST will receive a control number and may access the Annual Meeting as described in the paragraph above for stockholdersof record.

Our virtual Annual Meeting allows stockholders to submit questions and comments before and during the Annual Meeting. Stockholders who have accessed the Annual Meeting with a control number may submit questions during the Annual Meeting that are pertinent to the Company and the items being brought before a vote at the Annual Meeting, as time permits and in accordance with our rules of procedure for the Annual Meeting. If you wish to submit a question, you may do so when you are logged into the virtual meeting platform with your control number by typing your question in the designated spot on the dashboard and clicking “Submit.” After the Annual Meeting, we will spend up to 15 minutes answering stockholder questions that comply with the rules of conduct for the Annual Meeting, which will be posted on the virtual meeting web portal. To the extent time doesn’t allow us to answer all of the appropriately submitted questions, we will answer them in writing on our investor relations website at http://investor.rubiconproject.com/ soon after the meeting. If we receive substantially similar questions, we will group such questions together and provide a single response to avoid repetition.

Voting and Quorum Requirements

On March 18, 2019,May 14, 2020, the record date for the determination of stockholders entitled to notice of and to vote at the Annual Meeting, there were outstanding and entitled to vote an aggregate of 51,804,341of107,406,428 shares of our common stock, constituting all of our voting stock. Holders of our common stock are entitled to one vote per share. The holders of a majority of the shares of our common stock outstanding on the record date and entitled to vote at the Annual Meeting, present in personvia live webcast or by proxy, will constitute a quorum for the transaction of business at the Annual Meeting and any adjournments and postponements thereof. Shares of our common stock represented in person or by proxy (including broker non-votes and shares that abstain or do not vote with respect to one or more of the matters presented for stockholder approval) will be counted for purposes of determining whether a quorum is present at the AnnualtheAnnual Meeting.

You may vote FOR, AGAINST or ABSTAIN with respect to each director nominee (Proposal 1) and, ratification of the selection of Deloitte & Touche LLP as our independent registered public accounting firm for the current fiscal year (Proposal 2), and approval of the compensation of the company’s named executive officers (Proposal 3). You may vote 1 YEAR, 2 YEARS,3 YEARS or ABSTAIN with respect to the frequency of future advisory votes on the compensation of the company’s named executive officers (Proposal 4).

This is an uncontested election and our bylaws provide that a director nominee will be elected in an uncontested election only if the number of votes cast FOR the nominee’s election exceeds the number of votes cast AGAINST the nominee’s election, assuming a quorumaquorum is present. For the election of directors, shares of our common stock voted ABSTAIN and broker non-votes are not counted as votes cast and, therefore, will not be counted in determining the outcome of a director nominee’s election, but will count for purposes of determining whether a quorum exists. quorumis present.

The affirmative vote of a majority of the shares of our common stock present in person or represented by proxy and entitled to vote on the matter, assuming a quorum is present, is required to (i) ratify the selection of Deloitte & Touche LLP as our independent registered public accounting firm for the current fiscal year. year (Proposal 2), (ii) approve, on an advisory basis, the compensation of the company’s named executive officers (Proposal 3) and (iii) approve the frequency of future advisory votes on the compensation of the company’s named executive officers (Proposal 4). However, if no frequency option receives the affirmative vote of a majority of the shares of common stock represented at the Annual Meeting and entitled to vote on Proposal 4, our board of directors will consider the option receiving the highest number of affirmative votes as the preferred frequency option ofour stockholders.

For each of Proposals 2, 3 and 4, abstentions are considered shares present and entitled to vote on such matter. For each of Proposals 2 and 3, abstentions will have the same effect as votes AGAINST the matter. For Proposal 4, abstentions will not be counted in determining the outcome of the preferred frequency of stockholder advisory votes on the compensation of the company’s namedexecutive officers.

Votes at the Annual Meeting will be tabulated by a representative of American Stock Transfer & Trust Company, who will serve as the Inspector of Elections. Our intention is to announce the preliminary voting results at the Annual Meeting and to publish the final results within four business days after the Annual Meeting on a Form 8-K to be filed with the SEC and which we will make available on ourwebsite at http://investor.rubiconproject.com/.

Broker Discretionary Voting

If you hold your shares in street name through a bank, broker, or other nominee, you should follow the instructions that you receive from your bank, broker, or other nominee regarding steps to take to instruct your bank, broker, or other nominee how to vote your shares. If you do not provide voting instructions, your bank, broker, or other nominee is permitted to use its own discretion and vote your shares only on routine matters. However, for non-routine matters, your bank, broker, or other nominee does not have discretionary authority to vote your shares. The election of directors (Proposal 1), the approval, on an advisory basis, of the compensation of the company’s named executive officers (Proposal 3) and the indication, on an advisory basis, of the preferred frequency of stockholder advisory votes on the compensation of the company’s named executive officers (Proposal 4) are each considered a non-routine matter, so brokers are not permitted to vote your shares with respect to such matters without receiving voting instructions from you. The ratification of the selection of Deloitte & Touche LLP as our independent registered public accounting firm abstentions arefor the current fiscal year (Proposal 2) is considered shares present and entitleda routine matter. If your broker exercises its discretion to vote on Proposal 2 at the Annual Meeting, your shares will be voted on such matter and thusproposal in the manner directed by your broker, but your shares will have the same effectconstitute “broker non-votes” on each other proposal voted on at theAnnual Meeting.

Broker non-votes will not be counted as votes AGAINSTcast with respect to the matter.election of directors (Proposal 1) and, therefore, will not be counted in determining the outcome of a director nominee’s election. For approval, on an advisory basis, of the compensation of the company’s named executive officers (Proposal 3) and approval, on an advisory basis, of the frequency of future of advisory votes on the compensation of the company’s named executive officers (Proposal 4), broker non-votes will not be counted in determining the outcome ofthose items.

Deadline for Voting

If you are a stockholder of record, your proxy must be received by telephone or the Internet byInternetby 11:59 p.m. Eastern time on May 14, 2019 onJune 30, 2020in order for your shares to be voted at the Annual Meeting. If you are a stockholder of record and you received a printed set of proxy materials, you also have the option of completing, signing, dating and returning the proxy card enclosed with the proxy materials before the Annual Meeting in order for your shares to be voted at the meeting. If you are a beneficial owner of shares of our common stock, please comply with the deadlines included in the voting instructions provided by the bank, broker or other nominee that holds yourholdsyour shares.

Changing or Revoking Your Vote

If you are a stockholder of record you may revoke a previously submitted proxy by delivery of(i) delivering a subsequently dated written revocation to our Secretary, (ii) providing subsequent Internet or telephone voting instructions, or (iii) delivering a subsequently dated proxy to our Secretary, in each case,by 11:59 p.m. Eastern Time on May 14, 2019 orJuly 7, 2020. You may also revoke your proxy by voting in person at the Annual Meeting. If your shares are held through a bank or broker (i.e., in street name), you must contact your broker, bank or other nominee to find out how to change or revoke your voting instructions. Attendance at the Annual Meeting will not cause your previously executed proxy to be revoked unless you vote in person or specifically request such revocation. Each stockholder may appoint only one proxy holder or representative to attend the meeting on his or herorher behalf.

Broker Discretionary Voting

If you hold your shares in street name through a bank, broker, or other nominee, you should follow the instructions that you receive from your bank, broker, or other nominee regarding steps to take to instruct your bank, broker, or other nominee how to vote your shares. If you do not provide voting instructions, your bank, broker, or other nominee is permitted to use its own discretion and vote your shares only on routine matters. However, for

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non-routine matters, your bank, broker, or other nominee does not have discretionary authority to vote your shares. The election of directors is considered a non-routine matter, so brokers are not permitted to vote your shares with respect to that matter without receiving voting instructions from you. The ratification of the selection of Deloitte & Touche LLP as our independent registered public accounting firm for the current fiscal year is considered a routine matter. If your broker exercises its discretion to vote on routine matters at the Annual Meeting, your shares will be voted on the routine matters in the manner directed by your broker, but your shares will constitute “broker non-votes” on each non-routine item to be voted on at the Annual Meeting.

Householding of Proxy Materials

Some banks, brokers, and other nominee record holders may participate in the practice of “householding” proxy materials. This means that only one copy of our proxy materials or the Notice of Internet Availability of Proxy Materials, as applicable, may have been sent to multiple stockholders in your household unless such stockholders have notified us of their desire to receive multiple copies of our proxy materials. We will promptly deliver a separate Notice of Internet Availability of Proxy Materials and, if applicable, a separate proxy statement and Annual Report, to you if you contact us by mail at TheatThe Rubicon Project, Inc., 12181 Bluff Creek Drive, 4th Floor, Los Angeles, California 90094, Attention: Corporate Secretary or by telephone at (310)at(310) 207-0272. If you want to receive separate copies of our proxy materials in the future, or if you are receiving multiple copies and would like to receive only one copy for your household, you should contact your bank, broker, or other nominee record holder, or you may contact us at the above address or phoneorphone number.

Explanatory Note

We are an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act (the “JOBS Act”). As an emerging growth company, we provide in this Proxy Statement the scaled disclosure permitted under the JOBS Act. In addition, as an emerging growth company, we are not required to conduct votes seeking approval, on an advisory basis, of the compensation of our named executive officers or the frequency with which such votes must be conducted.

Under the JOBS Act, we will remain an “emerging growth company” until the earliest of: (i) the last day of the fiscal year during which we have total annual gross revenue of $1.07 billion or more; (ii) the last day of the fiscal year following the fifth anniversary of the closing of our initial public offering on April 7, 2014; (iii) the date on which we have, during the previous three-year period, issued more than $1 billion in non-convertible debt; and (iv) the date on which we are deemed to be a “large accelerated filer” under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) (we will qualify as a large accelerated filer as of the first day of the first fiscal year after we have more than $700 million in outstanding common equity held by our non-affiliates and which is measured each year on the last day of our immediately preceding second fiscal quarter).

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PROPOSAL 1 — ELECTION OF DIRECTORS

Our board of directors is classified into three classes (designated Class I, Class II and Class III), with members of each class holding office for staggered three-year terms.There are currently twothree Class I directors, whose terms expire at the 2021 Annual Meeting;annual meeting of the stockholders; three Class II directors, whose terms expire at the Annual Meeting;2022 annual meeting of the stockholders; and three Class III directors, whose terms expire at the 2020 annual meeting of stockholders,Annual Meeting, in all cases subject to the election and qualification of their respective successors and to their earlier death, resignation or removal. Sumant Mandal, a Class II director, will not stand for re-election and his term will expire at the Annual Meeting. If the two Class II director nominees are elected to the board of directors at the Annual Meeting, we will have one vacancy on our board of directors immediately following the Annual Meeting. Proxies cannot be voted for a greater number of persons than thenominees named.

On April 1, 2020, the nominees named.

company completed its merger with Telaria, Inc. (“Telaria”), with Telaria continuing as a wholly owned subsidiary of Rubicon Project. Upon effectiveness of our merger with Telaria, Frank Addante and Lewis W. Coleman resigned from the company’s board of directors, andPaul Caine, Doug Knopper, Rachel Lam and James Rossman, each a Telaria director prior to our merger with Telaria, were elected to the company’s board of directors to serve until their respective successors have been duly elected and qualified, or until any such new director’s earlier death, resignationor removal.

Our process for nominating director candidates is described below under the caption “Director Candidate Nominating Procedures.” Our board of directors, upon the recommendation of the nominating & governance committee, nominated incumbents Messrs. Barretteach of Paul Caine, Doug Knopper and SpillaneLisa L. Troe to stand for election as Class IIIII directors at the Annual Meeting. Each nominee has indicated his or her willingness to serve if elected, but if hehe/she is unable or unwilling for good cause to serve, proxies may be voted for a substitute nominee designated by our board of directors or theour board of directors may determine to reduce the size of the board. Each nominee, if elected, will hold office until the 20222023 annual meeting of stockholders, subject to the election and qualification of his respective successor and to his earlier death, resignation orresignationor removal.

The table below lists the sevennine directors expected to continue in service following the Annual Meeting and their committee assignments. A summary of the background for each nominee and continuing director is set forth after the table. These background summaries include the specific experience, qualifications, attributes, and/or skills that, together with the general characteristics and qualifications described below under the caption “Director Candidate Nominating Procedures,” contributed to our board’s conclusion that the person should serve as a director of theofthe company.

(1)As of May14, 2020

Director Nominees – Class IIIII

Paul Cainehas been a member and Chairman of our board of directors since April 2020. Hepreviously served as the non-executive Chairman of Telaria from January 1, 2020 until April 2020 and as a member of Telaria’s board of directors from June 2014 until April 2020. He served as Telaria’s executive Chairman from July 2017 to December 31, 2019 and Telaria’s Interim Chief Executive Officer from February 2017 to July 2017 and as the non-executive Chairman of the Board from July 2016 to February 2017. Mr. Caine has served as President of On Location Experiences at Endeavor Group Holdings, Inc. since January 2020.Mr. Caine has served as theChairman andExecutive Director of the Board of Engine Group, a global marketing company, since January 2018, and as CEO and Founder of PC Ventures, LLC, an investment and advisory firm since August 2017. Mr. Caine served as the Chief Global Revenue Officer for Bloomberg Media from June 2014 to July 2016. From April 2013 to January 2014 he served as Chief Executive Officer and a member of the board of directors of WestwoodOne, Inc., the largest independent national audio media company in the U.S. From 1989 to 2013, Mr. Caine served in various capacities at TimeInc., including

Executive Vice President, Chief Revenue Officer and Group President Time Inc. from January 2011 until April 2013, Executive Vice President, President and Group Publisher, Style & Entertainment Group from January 2010 to January 2011, and President, Style & Entertainment Group from January 2008 to January 2010. From 2007 to 2011, Mr. Caine served on the board of directors of Nexcen Brands, Inc., a strategic brand management company with a focus on retail franchising, where he served as a member of the audit and governance committees. Mr. Caine received a B.A. in Telecommunications with a minor in Business from Indiana University. Mr. Caine brings to the board expertise in branding and multi-media advertising sales and marketing, as well extensive experience serving on the boards of directors of public andprivate companies.

Doug Knopper has been a member of our board of directors since April 2020. He previously served as a member of Telaria’s board of directors from October 2018 until April 2020. Mr. Knopper is the Co-Founder of FreeWheel Media, Inc. and served as its Co-Chief Executive Officer from February 2007 to September 2017. FreeWheel, which was acquired by Comcast in 2014, provides a technology platform for the management and monetization of digital television advertising. Prior to founding FreeWheel, Mr. Knopper served as the Chief Executive Officer of BitPass Inc. from 2005 to 2007 and as Senior Vice President/General Manager of DoubleClick Inc. from 2000 to 2005. Mr. Knopper received a B.A. from the University of Michigan and an M.B.A from Georgetown University. Mr. Knopper brings to the board deep expertise and business relationships in digital video advertising and CTV, as well as experience founding, building and leading advertisingtechnology companies.

Lisa L. Troe has been a member of our board of directors since February 2014. She is a Senior Managing Director and co-Founder of Athena Advisors LLC, a business advisory firm, a position she has held since January 2014. From October 2005 to December 2013, Ms. Troe was a Senior Managing Director at FTI Consulting, Inc., a global business advisory firm. From January 1995 to October 2005, Ms. Troe served on staff of the SEC’s Pacific regional office, including seven years as an Enforcement Branch Chief and six years as Regional Chief Enforcement Accountant. From November 2018 to September 2019, Ms. Troe served as a director and audit committee chair of TheraCann International Benchmark Corp. In 2007, Ms. Troe served as a member of the Special Litigation Committee of the board of a public gaming industry manufacturing company. From 2003 through 2014, Ms. Troe was a member of the advisory board that functioned for Texas general partnership Avalon Oil Company as the equivalent of a board of directors. Her career includes accounting positions in public and private companies and with a Big Four public accounting firm. Ms. Troe is an NACD Board Leadership Fellow, the highest level of director credentialing by National Association of Corporate Directors, CERT certified in cybersecurity, a member of NACD and a CPA. Ms. Troe brings to the board an extensive background in public company governance and oversight, enterprise risk and crisis management, and public company accounting, financial reporting and disclosure. She has diverse experience with a wide range of industries, allowing her to bring additional perspective to our board.

Incumbent Directors – Class I

Robert J. Frankenberg joined our board of directors in connection with our initial public offering in April 2014.Mr. Frankenberg has owned NetVentures, a management consulting and investment firm focused on the high-tech industry, since 1996. He served on the board of directors of public company Nuance Communications from March 2000 to June 2018. He previously served as a member of the boards of directors of public companies Polycom from October 2013 to September 2016, Wave Systems from December 2011 to June 2015 and National Semiconductor until October 2011. He also serves on the board ofVeracity Networksandthe Sundance Institute. Prior to its sale in 2004, Mr. Frankenberg chaired Kinzan, a leading provider of Internet services platforms. Mr. Frankenberg was the chairman, president, and CEO of Encanto Networks from June 1997 to July 2000 when the company’s major business was sold to Avaya. Encanto was a leading provider of eBusiness software and services to small business. From April 1994 to August 1996,Mr. Frankenberg was the Chairman/CEO of Novell, a networking software company. Prior to Novell, Mr. Frankenberg was the Vice President & Group General Manager of Hewlett-Packard’s Personal Information Products Group, responsible for HP’s personal computer, server, networking, office software, calculator, and consumer product lines. Mr. Frankenberg joined Hewlett-Packard in 1969 as a manufacturing technician, later became a design engineer, software designer, project manager, engineering and marketing executive, and general manager. He became a corporatevice president in 1990 and general manager of the Personal Information Products Group in 1991. He served in the US Air Force from 1965 to 1969. Mr. Frankenberg previously served on various other boards, including for America OnLine (AOL), and holds several computer design patents. He brings to the board a deep knowledge of software, computer networks and systems, business operations, the technology industry, and public company governance andboard service.

Sarah P. Harden joined our board of directors in July 2019. Ms. Harden brings more than two decades of experience in digital media, entertainment and direct-to-consumer video to the Company’s Board. Since January 2018, Ms. Harden has served as the Chief Executive Officer of Reese Witherspoon’s media company Hello Sunshine. Prior to that, Ms. Harden held executive-level positions at Otter Media/The Chernin Group from 2013 to 2018, including President and Executive Vice President.Ms. Harden previously served as board member of privately held ESPN-Star Sports, Star China Media and The Moby Group and asa board

director overseeing successful acquisitions and exits of private portfolio companies including Crunchyroll, Fullscreen, Roosterteeth, McBeard, Stagebloc and minority-invested company DLVR. Ms. Harden received her MBA from Harvard Business School and graduated with honors with a B.A. in international relations from The University of Melbourne. Ms. Harden brings to the board extensive experience leading and growing digital video, media andentertainment companies.

James Rossman has been a member of our board of directors since April 2020. Hepreviously served as a member of Telaria’s board from January 2011 until April 2020, and served as Chairman of Telaria’s board from August 2012 to May 2013.Mr. Rossman currently serves as an Operating Partner atSilver Lake Partners.From November 2012 to April 2018, he served as Special Advisor to General Atlantic, a global growth equity firm. From April 2009 to June 2012, he served in various roles at AKQA Inc., a digital services company, including President and Chief Operating Officer. From April 2001 to March 2009, Mr. Rossman served in several roles at Digitas, Inc., an integrated advertising agency and a member of the Publicis Groupe, S.A. (as of 2007), including as Chief Operating Officer. Mr. Rossman received a B.A. in economics from Trinity College and an M.M.M. from the Kellogg School of Management at Northwestern University. Mr. Rossman brings significant experience in operating and managing media agencies and advertisingtechnology companies.

Incumbent Directors – Class II

Michael G. Barrett has been a member of our board of directors and has served as our President and Chief Executive Officer since March 2017. He previously served as our President from March 2017 until April 2020. Mr. Barrett has served as the President of Ichabod Farm Ventures LLC, an investment company that he founded, since December 2012. From January 2014 to December 2015, he served as President and Chief Executive Officer of Millennial Media, Inc. From July 2012 to December 2012, Mr. Barrett served as Global Chief Revenue Officer and Executive Vice President at Yahoo! Inc. Prior to Yahoo!, from January 2012 to July 2012, Mr. Barrett served as Director at Google Inc., where he led the integration efforts following Google’s acquisition of AdMeld Inc., a global supply side platform solution for premium publishers. Mr. Barrett previously served as Chief Executive Officer at AdMeld from November 2008 to December 2011.

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Mr. Barrett also held senior positions at AOL, Fox Interactive Media and Disney Online. Mr. Barrett servesBarrettserved on the board of directors of Media Math, a demand-side platform.platform, from January 2013 to April 2020. Mr. Barrett brings to the board extensive experience in digital advertising and advertising technology, as well as significant executive managementexecutivemanagement expertise.

Rachel Lam has been a member of our board of directors since April 2020. Shepreviously served as a member of Telaria’s board since May 2013. Ms. Lam is the Co-Founder and Managing Partner of Imagination Capital, an early stage venture capital firm founded in 2017. From 2003 to 2017, Ms. Lam served as Group Managing Director of the Time Warner Investments Group, the strategic investing arm of Time Warner Inc.She managed Time Warner’s investments in numerous digital media companies, and served on the board of directors of privately held Maker Studios and Bluefin Labs prior to their sales to the Walt Disney Company and Twitter, respectively. Ms. Lam currently serves on the board of directors of The Center for Reproductive Rights as well as nonprofit news organization The City. Ms. Lam received a B.S. in industrial engineering and operations research from U.C. Berkeley and an M.B.A. from Harvard Business School. Ms. Lam brings to the board extensive experience investing in early and late stage digital media and technology companies, as well experience in banking and mergersand acquisitions.

Robert F. Spillane joined our board of directors in connection with our initial public offering in April 2014. From 1998 to 2017, Mr. Spillane was a Managing Principal at DigaComm, L.L.C., a private investment firm that leads early-stage venture capital transactions, primarily involving companies in technology and digital media. Mr. Spillane was formerly a Principal and President and CEO of the investment group DM Holdings, Inc., which was formed in 1991 to acquire Donnelley Marketing, Inc. from ThefromThe Dun and Bradstreet Corporation. Donnelley Marketing was a leading direct marketing and information services company. Mr.company.Mr. Spillane served as President and CEO, and on the board of directors of Donnelley Marketing, Inc. Prior to joining DMjoiningDM Holdings, Mr. Spillane was the Executive Vice President of Diamandis Communications, Inc., then a leading consumer magazine publisher, formed in 1987 in a leveraged buyout of CBS Magazines from CBS Inc., and also served as a member of the Diamandis board of directors from 1987 to 1990. Prior to Diamandis, Mr. Spillane held various executive positions with CBS, Inc., including Senior Vice President Group Publisher, Vice President of Circulation, Vice President General Manager of the CBS Special Interest Magazine Group, and Vice President Sales and Marketing of Fawcett Books. His ten-year career at CBS culminated in service from 1985 to 1987 as Senior Vice President, Publishing of CBS Magazines. In that capacity, he was directly responsible for 10 magazines. From 1972 to 1977, Mr. Spillane held various positions with Chesebrough Ponds, Inc. Mr. Spillane also served on the board of directors of TVSM, Inc., a private media company, from1992-1998.from 1992-1998. Mr. Spillane brings to the board expertise in the publishing and advertising businesses, as well as significant experience with operations and mergers andmergersand acquisitions.

Incumbent Directors – Class I

Frank Addante is our founder and has been a member and Chairman of our board of directors since 2007 and served as our Chief Executive Officer from April 2007 to March 2017 and our Chief Product Architect from November 2014 to February 2016. From March 2017 to June 2018, he was employed by the company, reporting to and assisting the Chief Executive Officer, including by providing analysis and advice in the areas of strategy, innovation, and advertising technology market conditions and dynamics. In 2002, Mr. Addante founded the email infrastructure provider StrongMail Systems, Inc. From January 1998 to November 2000, Mr. Addante was CTO and Technology Founder of L90, an Internet advertising company, where he pioneered one of the Internet’s first ad serving platforms, adMonitor. Mr. Addante started his Internet career with the creation of Starting Point, a search engine. Mr. Addante brings to our board of directors thorough knowledge of our company and extensive experience in advertising automation and related systems engineering, innovation, and executive leadership.

Robert J. Frankenberg joined our board of directors in connection with our initial public offering in April 2014. Mr. Frankenberg has owned NetVentures, a management consulting and investment firm focused on the high-tech industry, since 1996. He served on the board of directors of public company Nuance Communications from March 2000 to June 2018. He previously served as a member of the boards of directors of public companies Polycom from October 2013 to September 2016, Wave Systems from December 2011 to June 2015 and National Semiconductor until October 2011. He also serves on the boards of private companies Veracity Networks, SQLStream, and Sylvan Source, as well as the Sundance Institute board. Prior to its sale in 2004, Mr. Frankenberg chaired Kinzan, a leading provider of Internet services platforms. Mr. Frankenberg was the chairman, president, and CEO of Encanto Networks from June 1997 to July 2000 when the company’s major business was sold to Avaya. Encanto was a leading provider of eBusiness software and services to small business. From April 1994 to August 1996, Mr. Frankenberg was the Chairman/CEO of Novell, a networking software company. Prior to Novell, Mr. Frankenberg was the Vice President & Group General Manager of Hewlett-Packard’s Personal Information Products Group, responsible for HP’s personal computer, server, networking, office software, calculator, and consumer product lines. Mr. Frankenberg joined Hewlett-Packard in 1969 as a manufacturing technician, later became a design engineer, software designer, project manager, engineering and marketing executive, and general manager. He became a corporate vice president in 1990 and general manager of the Personal Information Products Group in 1991. He served in the US Air Force from 1965 to 1969. Mr. Frankenberg previously served on various other boards, including for America OnLine (AOL), and holds several computer design patents. He brings to the board a deep knowledge of software, computer networks and systems, business operations, the technology industry, and public company governance and board service.

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Incumbent Directors – Class III

Lewis W. Coleman has been a member of our board of directors since December 2015. He is the retired Vice Chairman of DreamWorks Animation, a position he held from July 2014 to January 2015. Prior to that, he served in various executive-level positions with DreamWorks since December 2005, including as President from December 2005 to August 2014, Chief Financial Officer from February 2007 to September 2015, and acting Chief Accounting Officer from June to September 2014. Prior to joining DreamWorks, Mr. Coleman was the President of the Gordon and Betty Moore Foundation from its founding in November 2000 to December 2004. Prior to that, Mr. Coleman was a Senior Managing Director at Montgomery Securities and then President and Chief Operating Officer of its successor, Banc of America Securities, where he also served as Chairman from 1998 to 2000. Before then, Mr. Coleman spent ten years at Bank of America where he served as Vice Chairman and Chief Financial Officer. He spent the previous 21 years at Wells Fargo Bank, where his positions included Chief Credit Officer and Chairman of the Credit Policy Committee, and at Bank of California. Mr. Coleman currently serves on the board of directors of Immune Design, a publicly traded clinical-stage immunotherapy company focused on oncology, as well as DCI, LLC, a private fund management company, and Vista Capital Advisors (formerly eBond Advisors), a private financial technology company. Mr. Coleman’s previous board experience includes Chiron Corporation, Regal Entertainment, Bank of America, DreamWorks Animation and Northrop Grumman, where he was the Lead Independent Director. Mr. Coleman brings to the board an extensive background in consumer media and technology, and successful track record of expanding businesses into emerging markets, as well as significant executive level and public company board experience.

Lisa L. Troe has been a member of our board of directors since February 2014. She is a Senior Managing Director and co-founder of Athena Advisors LLC, a business advisory firm, a position she has held since January 2014. From October 2005 to December 2013, Ms. Troe was a Senior Managing Director in the forensic and litigation consulting practice at FTI Consulting, Inc., a global business advisory firm. From January 1995 to October 2005, Ms. Troe served on the staff of the Division of Enforcement of the SEC’s Pacific regional office, including seven years as an enforcement branch chief and six years as regional chief enforcement accountant. Ms. Troe serves as a director and audit committee chair of TheraCann International Benchmark Corporation. Her career includes accounting positions in public and private companies and with a Big Four public accounting firm. Ms. Troe is a credentialed National Association of Corporate Directors Governance Fellow and member of the National Association of Corporate Directors, a CPA, and member of the American Institute of CPAs. In 2017, Ms. Troe completed the National Association of Corporate Directors Cyber-Risk Oversight Program and received a CERT Certificate in Cybersecurity Oversight from the Software Engineering Institute of Carnegie Mellon University. Ms. Troe brings to the board an extensive background in public company governance and oversight, enterprise risk and crisis management, and public company accounting and financial reporting, as well as a diverse experience with many industries allowing her to bring additional perspective to our board.

Vote Required and Recommendationfor Election of our Board of Directors

Our bylaws provide that, in an uncontested election, each director nominee must receive a majority of votes cast in order to be elected to our board of directors. A “majority of votes cast” means the number of shares voted FOR a director nominee exceeds the number of shares voted AGAINST that director nominee. Each of our director nominees currently serves on the board. If a nominee who currently serves as a director is not re-elected, Delaware law provides that the director would continue to serve on the board as a “holdover director.” Our Corporate Governance Guidelines provide that each incumbent director nominee who is not re-elected is expected to submit to the board his or her resignation from our board of directors and all committees thereof. The nominating & governance committee, composed entirely of independent directors, will evaluate and make a recommendation to the board with respect to any submitted resignation and the board must decide whether to accept or reject the resignation, or to take other action, within 90 days following certification of the stockholder vote. No director may participate in the nominating & governance committee or the board’s consideration of his or her ownherown resignation.

The board of directors recommends a vote FOR“FOR” the election of each of Messrs. BarrettPaul Caine, Doug Knopper and SpillaneLisa L. Troe as Class IIIII directors.

PROPOSAL 2 — RATIFICATION OF THE SELECTION OF DELOITTE & TOUCHE LLP
AS INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The audit committee of our board of directors has selected Deloitte & Touche LLP (“Deloitte”) as our independent registered public accounting firm for the year ending December 31, 2020, and has further directed that management submit the selection of Deloitte as our independent registered public accounting firm for ratification by the stockholders at the Annual Meeting. Deloitte has served as our independent registered public accounting firm since 2018. PricewaterhouseCoopers LLP (“PwC”) previously served as our independent registered public accounting firm from 2012 to 2018. Although stockholder approval of the selection of Deloitte is not required by law, our board of directors believes it is advisable as a matter of good corporate governance to give stockholders an opportunity to ratify this selection. If this proposal is not ratified at the Annual Meeting, the audit committee may (but will not be required to) reconsider its selection of Deloitte. Even if the selection is ratified, the audit committee may in its discretion select a different independent registered public accounting firm at any time during the year if it determines that such a change wouldbe appropriate.

Representatives of Deloitte are expected to be present at the Annual Meeting and will have the opportunity to make a statement if they desire to do so and will also be available to respond to appropriate questions from stockholders. Representatives of PwC are not expected to be present at theAnnual Meeting.

Change of Independent Public Accounting Firm

As previously reported in our Current Report on Form 8-K, dated August 23, 2018 (the “Current Report”) and our 2018 proxy statement, the audit committee, with management’s assistance, conducted a competitive auditor review and selection process in order to select the firm to serve as our independent registered public accounting firm for the fiscal year ending December 31, 2018. The audit committee invited several firms to participate in this review process. As a result of this process, the audit committee made the decision to dismiss PwC as our independent registered public accounting firm on August 17, 2018, and informed PwC that they were dismissed on August17, 2018.

PwC’s audit reports on the Company’s consolidated financial statements as of and for the fiscal year ended December 31, 2017 did not contain any adverse opinions or disclaimers of opinion and were not qualified or modified as to uncertainty, audit scope oraccounting principles.

During the fiscal year ended December 31, 2017 and the interim period from December 31, 2017 through and including August 17, 2018, there were (i) no disagreements between the company and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure, which disagreements, if not resolved to the satisfaction of PwC, would have caused PwC to make reference to the subject matter of the disagreement in their reports on our consolidated financial statements for such year or any subsequent interim period through the date of dismissal, and (ii) no “reportable events” as that term is defined in Item 304(a)(1)(v) ofRegulation S-K.

We provided PwC with a copy of the disclosures we made in the Current Report prior to the time the Current Report was filed with the SEC. We requested that PwC furnish a letter addressed to the SEC stating whether or not it agrees with the statements made in the Current Report. A copy of PwC’s letter, dated August 23, 2018, was attached as Exhibit 16.1 to the Current Report and confirmed that they agreed with the statements we made in theCurrent Report.

On August 17, 2018, the audit committee appointed Deloitte as our independent registered public accounting firm for the fiscal year ending December 31, 2018. During the fiscal year ended December 31, 2017, and the subsequent interim period through August 17, 2018, neither the company nor anyone acting on our behalf consulted with Deloitte on any of the matters or events set forth in Item 304(a)(2)(i) or 304(a)(2)(ii) ofRegulation S-K.

Independent Registered Public Accounting Firm Fees

The aggregate fees billed for audit and other services provided in the last two fiscal years by Deloitte areas follows:

The aggregate fees billed for audit and other services provided in the last two fiscal years by PwC areas follows:

7(1)Audit Fees cover professional services rendered for the audit of our annual financial statements and review of financial statements included in our quarterly reports on Form 10-Q, and services normally provided by the accountant in connection with statutory and regulatory filingsor engagements.

(2)Audit-Related Fees cover assurance and related services that are reasonably related to the performance of audit or review of our financial statements and not reported asAudit Fees.

(3)Tax Fees cover tax compliance, advice, and planning services and consisted primarily of review of consolidated federal income tax returns and foreigntax issues.

(4)All Other Fees in 2019 and 2018 related to license fees for accountingresearch software.

Pre-Approval Policy and Procedures

The audit committee has adopted policies and procedures relating to the pre-approval of all audit and non-audit services that are to be provided by our independent registered public accounting firm. The audit committee will not approve non-audit services that the independent registered public accounting firm is not permitted to perform under the rules of the SEC and Public Company AccountingOversight Board.

On an annual basis, the independent registered public accounting firm will propose to the audit committee an audit plan and engagement letter describing the services the auditor expects to provide and related fees. The final engagement letter and fees agreed by Rubicon Project acting pursuant to the direction of the audit committee, and all of the services covered by the final engagement letter, will be considered pre-approved by theaudit committee.

The audit committee or the Chair of the audit committee acting by delegated authority will approve, if necessary, any changes in terms, conditions and fees under the engagement letter resulting from changes in the audit scope, company structure orother matters.

The audit committee has delegated to the Chair of the audit committee the authority to approve on a case-by-case basis any audit or non-audit services, in amounts up to $200,000 (1) per engagement, (2) per additional category of services, or (3) in excess of pre-approved amounts for the specified service. The Chair then reports any services so approved to the audit committee at its next regularlyscheduled meeting.

All services rendered for fiscal 2019 and fiscal 2018 were pre-approved by the audit committee in accordance with the audit committee’s pre-approval policies and proceduresdescribed above.

Vote Required for Ratification of the Selection of our Independent Registered Public Accounting Firm

Ratification of the selection of our independent registered public accounting firm requires the affirmative vote of a majority of the shares represented at the Annual Meeting, either in person or by proxy, and entitled to vote on the proposal. Abstentions will be considered as a vote “AGAINST”this proposal.

The board of directors recommends that stockholders vote “FOR” the ratification of the selection of Deloitte as our independent registered publicaccounting firm.

PROPOSAL 3 — ADVISORY VOTE TO APPROVE THE COMPENSATION OF OURNAMED
EXECUTIVE OFFICERS

Under the Dodd-Frank Wall Street Reform and Consumer Protection Act, or the Dodd-Frank Act, and Section 14A of the Exchange Act of 1934, as amended (the “Exchange Act”), the company’s stockholders are entitled to vote to approve, on an advisory basis, the compensation of the company’s named executive officers as disclosed in this proxy statement in accordance withSEC rules.

This vote is not intended to address any specific item of compensation, but rather the overall compensation of the company’s named executive officers and the philosophy, policies and practices described in this proxy statement. The compensation of the company’s named executive officers subject to the vote is disclosed in the executive compensation tables and the related narrative disclosure contained in this proxy statement.  As discussed in those disclosures, the company believes that its compensation policies and decisions are focused on motivating employees through performance-based variable compensation while ensuring that executives are strongly aligned with the creation of long-term value for stockholder principles.  Compensation of the company’s named executive officers is designed to enable the company to attract and retain talented and experienced executives to successfully lead the company in acompetitive environment.

Accordingly, the board of directors is asking the stockholders to indicate their support for the compensation of the company’s named executive officers as described in this proxy statement by casting a non-binding advisory vote “FOR” thefollowing resolution:

“RESOLVED, that the compensation paid to the Company’s named executive officers, as disclosed pursuant to Item 402 of Regulation S-K, including the compensation tables and narrative discussion ishereby APPROVED.”

Because the vote is advisory, it is not binding on the board of directors or the company. Nevertheless, the views expressed by the stockholders, whether through this vote or otherwise, are important to management and the board of directors and, accordingly, the board of directors and the compensation committee intend to consider the results of this vote in making determinations in the future regarding executivecompensation arrangements.

Vote Required for Approval, on an Advisory Basis, of the Compensation of our Named Executive Officers

Approval, on an advisory basis, of the compensation of our named executive officers requires the affirmative vote of a majority of the shares represented at the Annual Meeting, either in person or by proxy, and entitled to vote on the proposal. Abstentions will have the effect of a vote “AGAINST” thisproposal.   

The board of directors recommends that stockholders vote “FOR” the APPROVAL, ON AN ADVISORY BASIS, OF the compensation of the company’s namedexecutive officers.

PROPOSAL 4 — ADVISORY VOTE ON THE FREQUENCY OF FUTURE ADVISORY VOTES ON THE
COMPENSATION OF OUR NAMED EXECUTIVE OFFICERS

The Dodd-Frank Act and Section 14A of the Exchange Act also enable the company’s stockholders, at least once every six years, to indicate their preference regarding how frequently the company should solicit a non-binding, advisory vote on the compensation of the company’s named executive officers as disclosed in the company’s proxy statement (a “Say-on-Pay” vote). Accordingly, the company is asking stockholders to indicate whether they would prefer an advisory vote every year, every other year or every three years. Alternatively, stockholders may abstain from castinga vote.

The board of directors believes that an annual advisory vote on the compensation of the company’s named executive officers will allow our stockholders to provide timely and direct input on our executive compensation philosophy, policies and practices, which is consistent with our efforts to engage in an ongoing dialogue with our stockholders on executive compensation and corporategovernance matters.

While the board of directors believes that its recommendation is appropriate at this time, the stockholders are not voting to approve or disapprove that recommendation, but are instead asked to indicate their preferences, on an advisory basis.  Because we value the opinions of our stockholders, the board of directors and our compensation committee will consider the outcome of the Say-on-Frequency vote when determining the frequency by which we will hold Say-on-Pay votes inthe future.

Vote Required for Approval, on an Advisory Basis, of the Frequency of Future Advisory Votes on the Compensation of our Named Executive Officers

Under our bylaws, approval, on an advisory basis, of the frequency of future advisory votes on named executive officer compensation requires the affirmative vote of a majority of the shares represented at the Annual Meeting, either in person or by proxy, and entitled to vote on the proposal. However, if no frequency option receives the affirmative vote of a majority of the shares of common stock represented at the Annual Meeting and entitled to vote on Proposal 4, our board will consider the option receiving the highest number of affirmative votes as the preferred frequency option of our stockholders. Abstentions will have no effect on the outcome ofProposal 4.

The board of directors recommends that stockholders vote “1 YEAR” AS the frequency of FUTURE ADVISORY VOTES ON THE COMPENSATION OF OUR NAMEDexecutive OFFICERS.

CORPORATE GOVERNANCE

Corporate Governance Guidelines

Our board of directors has developed corporate governance practices to help it fulfill its responsibility to stockholders to oversee the work of management in the conduct of our business and to seek to serve the long-term interests of stockholders.The Company’s corporate governance practices are memorialized in our Corporate Governance Guidelines which direct our board’s actions with respect to, among other things, the composition and director qualifications of our board of directors, the composition of the standing committees of our board of directors, director orientation and continuing education, stockholder communications with our board of directors, succession planning and the annual performance evaluation of our board of directors. A current copy of our Corporate Governance Guidelines is available on ourwebsite at http://investor.rubiconproject.com.

Director Independence

Rubicon ProjectOur common stock is listed on the New York Stock Exchange, which requires that a majority of a listed company’s board of directors be independent. In addition, the rules of the New York Stock Exchange require that, subject to specified exceptions, each member of a listed company’s audit, compensation and nominating/corporate governance committees be independent. Under the rules of the New York Stock Exchange, a director will only qualify as an “independent director” if the board of directors affirmatively determines that the director has no material relationship with the company (either directly or as a partner, stockholder, or officer of an organization that has a relationship with the Company).withthe company.

Our board of directors has undertaken a review of the independence of each director and considered whether each director has any material relationships with us. As a result of this review, our board of directors has determined that Mr. Frankenberg,Ms. Harden, Mr. Knopper, Ms. Lam, Mr. Rossman, Mr. Spillane and Ms. Troe and Messrs. Coleman, Frankenberg, Mandal, and Spillane are independent directors as defined under the applicable rules and regulations of the SEC and the listing requirements and rules of the New York Stock Exchange for purposes of service on the board.board of directors and its committees. Mr. Barrett is not considered independent because he currently serves as our Chief Executive Officer. Mr. Caine is not considered independent due to his previous service as Executive Chairman and Interim Chief Executive Officer of Telaria. In addition,our board of directors previously determined that Lewis W. Coleman and Sumant Mandal qualified as independent directors under the applicable rules of the New York Stock Exchange during their service on our board of directors in 2019 through the applicable dates of their resignation. Frank Addante was not considered independent under the applicable rules the New York Stock Exchange during his service on our board of directors in 2019 due to his prior service as our ChiefExecutive Officer.

Audit committee members must also satisfy the additional, heightened independence criteria set forth in Rule 10A-3 under the Exchange Act, which provides that a member of an audit committee of a listed company may not, other than in his or her capacity as a member of the audit committee, the board of directors, or any other board committee: (i) accept, directly or indirectly, any consulting, advisory, or other compensatory fee from the listed company or any of its subsidiaries; or (ii) be an affiliated person of the listed company or any of its subsidiaries. Our board of directors has determined that each of our audit committee members satisfies these heightenedindependence criteria.

Members of our compensation committee must also satisfy the additional, heightened independence criteria set forth under Rule 10C-1 of the Exchange Act and under the rules and regulations of the New York Stock Exchange. In determining independence for these purposes, a listed company’s board of directors must consider: (i) the source of all compensation paid by the company to a director serving on the compensation committee, other than compensation for serving on the board, including any consulting, advisory or other fees; and (ii) whether the director is an affiliated person of the listed company, any of its subsidiaries or any affiliate of a subsidiary. Our board of directors has determined that each of our compensation committee members satisfies these heightenedindependence criteria.

Board Leadership Structure

Our Corporate Governance Guidelines provide that our board of directors will determine in its discretion from time to time whether the roles of Chairman and Chief Executive Officer should be combined or separated. With the appointment of Mr. Barrett as Chief Executive Officer in March 2017, our board of directors determined to separate these roles and retained Mr. Addante as non-executive Chairman. Because ourOur board believes that strong, independent board leadership is a critical aspect of effective corporate governance, and to promote open discussion among our non-management directors, our Corporate Governance Guidelines provide that, when the Chairman is a non-independent director, the independent directors will designate an independent director to act asLead Director.

In April 2020, upon the completion of our merger with Telaria, Mr. Caine was appointed as Chairman of the board.The responsibilities of the Chairman include: (1) leading and presiding at board meetings; (2) assisting in establishing the agenda for each board meeting, with input from the Lead Director, as appropriate; (3) conferring regularly with CEO and consulting with the CEO regarding board meeting schedules and agendas; (4) presiding at executive sessions of the Board, otherthan sessions

consisting solely of independent directors; (5) consulting with committees of the board on matters within the scope of their responsibilities;(6) facilitating communications between directors and between directors and senior management; (7) providing feedback between the CEO and directors regarding strategic issues, board management, and potential conflicts; (8) working with appropriate committees of the board to ensure adequate CEO and senior management succession plans are in place; and (9) being available for consultation and communication with major stockholdersupon request.

Pursuant to our bylaws, until April 1, 2022, Mr. Caine will serve as Chairman of the board so long as he continues to serve as a member of the board of directors. If Mr. Caine ceases to be a member of the board of directors prior to April 1, 2022, then the board of directors, acting by the affirmative vote of both a majority of the then-serving Rubicon Project continuing directors and a majority of the then-serving Telaria continuing directors (each as further described below under “—Board Size and Composition”), will elect one of its members to be the Chairman ofthe board.

Because Mr. Caine is not deemed independent, Robert J. Frankenberg has been appointed and currently serves in the role of Lead Director.

The responsibilities of the Lead Director include: (1) presiding at executive sessions of the board in place of the Chairman, as well as at meetings of the board at whichindependent directors;(2) if the Chairman is not present, presiding at board meetings and meetingsexecutive sessions of independent or non-management directors; (2) approving information sent to the board; (3) approvingproviding input to the CEO and Chairman with respect to the board agenda and schedule for board meetings at which the Lead Director will preside, as well as other board meetings if the Chief Executive Officer and Chairman are the same person;schedule; (4) serving as liaison between the independent directors and the Chairman and/or Chief Executive Officer on sensitive matters; (5) being available for consultation and communication with major stockholders upon request; and (6) calling executive sessionsmeetings of independent directors; and (7) serving as designated director for reviewingstockholder communications.

Board Size and Composition

Our board of directors consists of nine members. Pursuant to our bylaws, our board of directors will continue to consist of nine directors until at least April 1, 2022, the second anniversary of the completion of our mergerwith Telaria.

Until April 1, 2022, our board and independent or non-management directors. The independentof directors have selectedwill be comprised of four Rubicon Project continuing directors (currently, Robert J. Frankenberg, Sarah P. Harden, Robert F. Spillane and Lisa L. Troe) (or, in the event of a vacancy among the Rubicon Project continuing directors, a replacement Rubicon Project continuing director proposed by a majority of the remaining Rubicon Project continuing directors), each of whom shall meet the independence standards of the New York Stock Exchange, four Telaria continuing directors (currently, Paul Caine, Doug Knopper, Rachel Lam and James Rossman) (or, in the event of a vacancy among the Telaria continuing directors, a replacement Telaria continuing director proposed by a majority of the remaining Telaria continuing directors), at least three of whom shall meet the independence standards of the New York Stock Exchange and our chiefexecutive officer.

Ms. Harden, who was appointed to serveour board of directors in July 2019, was initially identified as Lead Director because of his significant experience as botha potential director candidate by an executive officer andindependent director and his familiarity with technology companies and public company governance and board operation.search firm that was engaged by the nominating &governance committee.

Board and Committee Meetings

In 2018,2019, our board of directors met seven12 times, the audit committee met seven4 times, the compensation committee met seven5 times, and the nominating & governance committee met four times. The independent directors met in executive sessions without management in connection with four of the board meetings, five of the audit committee meetings, and three of the compensation committee meetings. During 2018,6 times.During 2019, each director attended at least 75% of the aggregate number of board meetings and meetings held by all committees on which the director then served withduring the exception of Mr. Coleman, who attended five of the seven (71%) audit committee meetings, and Mr. Mandal, who attended five of the seven (71%) compensation committee meetings.time in which he or she served on our boardof directors.

Our Corporate Governance Guidelines call for us to schedule annual meetings of stockholders to coincide when possible with one of the four regular quarterly board meetings. Directors are expected to attend the annual stockholders’ meeting absent unusual circumstances. A copy of the Corporate Governance Guidelines is posted on the “Corporate Governance” section of our Investor Relations website at http://investor.rubiconproject.com. All of our directors at the time of the 2019 annual meeting attended the 2018 annual2019annual meeting.

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Board Committees

Our board of directors has established three standing committees – audit, compensation, and nominating & governance – each of which operates under a written charter that has been approved by our board. Committee membership is indicated in the table above on page 5.above. A current copy of each committee’s charter is posted on the “Corporate Governance” section of our Investor Relations website athttp://investor.rubiconproject.com. Each committee reviews and evaluates, at least annually, the performance of the committee and its members and the adequacy of itsofits charter.

Audit Committee

The audit committee is responsible for, among other things, providing assistance to the board of directors in fulfilling its oversight responsibilities regarding the integrity of our financial statements, our compliance with applicable legal and regulatory requirements, the integrity of our financial reporting processes, including our systems of internal accounting and financial controls, the performance of our internal audit function and our independent registered public accounting firm, and our financial policy matters. The audit committee approves the services performed by our independent registered public accounting firm and reviews their reports regarding our accounting practices and systems of internal control over financial reporting, as applicable. The audit committee also oversees the audit efforts and confirms the independence of our independent registered public accounting firm. Our board of directors has determined that each member of our audit committee satisfies SEC requirements for independence and the independence and financial literacy requirements of the New York Stock Exchange, and that eachMs. Troe qualifies as an “audit committee financial expert,” as defined in the SECtheSEC rules.

Compensation Committee

The compensation committee is responsible for, among other things, overseeing our overall compensation structure, policies and programs, and assessing whether our compensation structure establishes appropriate incentives for officers and employees. Theemployees.The compensation committee also reviews and approves corporate goals and objectives relevant to compensation of our Chief Executive Officer and other executive officers, evaluates the performance of these officers in light of those goals and objectives, sets the compensation of these officers based on such evaluations and reviews, and, except with respect to his own compensation, based on the recommendation of the Chief Executive Officer, determines any employment-related agreements and any proposed severance arrangements or change in control or similar agreements with these officers. The compensation committee also administers the issuance of equity awards under our stock plans and is permitted to delegate such responsibility to our Chief Executive Officer with respect to employees other than executive officers. The compensation committee has delegated to our Chief Executive Officer authority to approve equity awards, subject to the following limitations: (1) no awards may be granted by the Chief Executive Officer to himself or herself, or to members of the board of directors or any executive officer; (2) no individual may be granted more than 100,000 shares in the aggregate in any rolling 365-day period; (3) no more than 250,000 shares may be granted in the aggregate to all recipients in any calendar quarter, or 1,000,000 shares in the aggregate in any calendar year; and (4) awards must be made on standard terms (e.g., four-year vesting) pursuant to the company’s standard award documents. The compensation committee is also responsible for the preparation of a report on executive compensation, when and as required by the SEC rules, to be included in our Annual Report and annual proxy statement. Our board of directors has determined that each member of our compensation committee satisfies the requirements for independence under the rules and regulations of both the New York Stock Exchange and the SEC, and is a non-employee director for purposes of Rule 16b-3 under the ExchangetheExchange Act.

The compensation committee has the authority, in its sole discretion, to retain or obtain the advice of such consultants, outside counsel and other advisers as it determines appropriate to assist it in the full performance of its functions, at the Company’s expense. Since December 2014, the compensation committee has engaged Semler Brossy Consulting Group, LLC (“Semler Brossy”) annually to act as its independent compensation consultant.During 2019, Semler Brossy’s work with the compensation committee included analysis, advice, and recommendations on total compensation philosophy; peer groups and market assessment and analysis; compensation program design, including program goals, components, and metrics; equity usage and allocation; compensation trends in comparable business sectors and in the general marketplace for senior executives; regulatory factors; and the compensation of the chief executive officer and the other named executive officers, including advice on the design of cash-basedand equity-based compensation.

Semler Brossy provides analysis and advice regarding our executive compensation practices, including with respect to the amount and form of executive and non-employee director compensation. A representative of Semler Brossy attends meetings at which the compensation committee undertakes significant review of, and/or action with respect to, executive officer or non-employee director compensation. Semler Brossy also consults regularly with the chair of the compensation committee. Semler Brossy reports directly and solely to the compensation committee and

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performs compensation consulting services for the compensation committee at its request. Semler Brossy is not engaged to perform services directly for our management. The compensation committee has concluded that no conflict of interest exists with respect to its engagement of Semler Brossy nor are there other factors that would adversely impact Semler Brossy’s independence in advising the compensation committee under applicable SEC and New York Stock Exchange rules. The compensation committee reached this conclusion after considering the following six factors, as well as Semler Brossy’s views regarding its independence and other information the compensation committee deemed relevant: (i) the provision of other services to us by Semler Brossy; (ii) the amount of fees received from us by Semler Brossy, as a percentage of the total revenue of Semler Brossy; (iii) the policies and procedures of Semler Brossy that are designed to prevent conflictspreventconflicts of

interest; (iv) any business or personal relationship of the Semler Brossy consultants with a member of the compensation committee; (v) any of our stock owned by the Semler Brossy consultants; and (vi) any business or personal relationship of the Semler Brossy consultants or Semler Brossy with any of our executiveourexecutive officers.

Nominating & Governance Committee

The nominating & governance committee is responsible for, among other things, developing and recommending to the board of directors criteria for identifying and evaluating candidates for directorships and making recommendations to the board of directors regarding candidates for election or reelection to the board of directors at each annual stockholders’ meeting. In addition, the nominating & governance committee is responsible for overseeing our Corporate Governance Guidelines and reporting and making recommendations to the board of directors concerning corporate governance matters. The nominating & governance committee also is responsible for making recommendations to the board of directors concerning the structure, composition and function of the board of directors and its committees. Our board of directors has determined that each member of our nominating & governance committee satisfies the requirements for independence under the rules and regulations of the New York StockYorkStock Exchange. The nominating & governance committee has engaged a search firm to assist the committee in the process of identifying and evaluating qualified potential director candidates to fill the seat vacated by Mr. Mandal.

Director Candidate Nominating Procedures

The process followed by the nominating & governance committee to identify and evaluate director candidates includes requests for recommendations (which may include through retained third-party search firms, as well as less formal methods such as personal contacts), committee meetings from time to time to evaluate biographical information and material relating to potential candidates, and interviews of candidates by board members. In 2019, the Nominating Committee engaged an independent director search firm to assist in identifying and evaluating director candidates. The firm aided the Committee in identifying and corresponding with potential director candidates, evaluating the candidates’ credentials, and facilitating conversations between potential director candidates and management and other members of our Board. In identifying and evaluating director candidates and determining whether to nominate any particular candidate, the nominating & governance committee considers the director candidates’ specific experience, qualifications, attributes and skills, together with the following general characteristics and qualifications, which are set forth in our Corporate GovernanceCorporateGovernance Guidelines:

•highest personal and professional ethics, integrity,and values;

10•independent, creative, and disciplinedthought processes;

•practical wisdom andmature judgment;

•willingness to devote the required amount of time to carrying out the duties and responsibilities ofboard membership;

•commitment to serve on the board over a period of several years to develop knowledge aboutthe company;

•unless management directors, independence under relevantstandards; and

•diversity of occupational and personal backgrounds among the members ofthe board.

While the nominating & governance committee does not have a formal policy regarding board diversity, it is a factor that the nominating & governance committee takes into account in identifying director nominees. The nominating & governance committee believes that diversity is important because different points of view and varied board member backgrounds and practical experience can contribute to the quality of the board’s operations and decision-making, and assesses board diversity, among other things, in its periodic assessment of the composition, operation, and effectiveness of theofthe board.

The nominating & governance committee does not assign specific weights to particular criteria, but does believe that the backgrounds and qualifications of our directors, considered as a group, should provide a composite mix of experience, knowledge and abilities that will facilitate our board’s fulfillment of itsofits responsibilities.

Stockholders may recommend individuals to the nominating & governance committee for consideration as potential director candidates and inclusion in our proxy statement for the 20202021 annual meeting of stockholders by submitting their names, together with appropriate biographical information and background materials. Such information should be sent to the Nominating & Governance Committee, c/o Corporate Secretary, The Rubicon Project, Inc., 12181 Bluff Creek Drive, 4th Floor, Los Angeles,California 90094.

Assuming that appropriate biographical and background material has been provided on a timely basis, the nominating & governance committee will evaluate stockholder-recommended candidates by following the same process, and applying the same criteria, as it follows for other candidates. If our board determines to nominate a stockholder-recommended candidate, then his or her name will be included in our proxy materials, including our proxy card, for the 20202021 annual meeting ofmeetingof stockholders.

Board Evaluation Process

Our board of directors and each of our standing committees conducts an annual self-evaluation to assess its performance. Each director participates in these evaluations and our Chairman or Lead Director, as applicable, and the Chair of the nominating & Governance committee then review and discuss the results with the full board. In addition, as part of the process of considering directors for re-election to the board, individual directors are annually informally evaluated by the nominating & governance committee on the basis of their attendance at meetings and their preparedness, participation, candor and overall contribution to the board, as well as other criteria that the nominating & governance committee deemscommitteedeems appropriate.

Communicating with the Independent Directors

Stockholders and other interested parties who wish to communicate on any topic with our board, or with a specific director or directors, including the Lead DirectorChairman or the independent directors as a group, may address such communications to our Boardboard of Directorsdirectors c/o Corporate Secretary, The Rubicon Project, Inc., 12181 Bluff Creek Drive, 4th Floor, Los Angeles,California 90094.

Our board of directors will give appropriate attention to written communications that are submitted by stockholders, and will respond if and as appropriate. The Lead Director, or the Chair of the nominating & governance committee, with the assistance of our General Counsel and Chief Financial Officer, is primarily responsible for reviewing communications from stockholders and for providing copies or summaries to the other directors as considered appropriate. In accordance with the procedures outlined in Rubicon Project’s Corporate Governance Guidelines, communications (or summaries thereof) that relate to corporate governance, long-term corporate strategy, and other important substantive matters should be forwarded to the other directors, unless there is a compelling reason not to forward such communications. In general, the director who reviews such communications may decline to forward communications that relate to ordinary business affairs or personal grievances, or are repetitive or duplicative, unless there is a compelling reason to forward suchforwardsuch communications.

Board’s Role in Risk Oversight

Our board of directors exercises oversight of risk management consistent with its duty to direct the management of the business and affairs of the company. The audit committee, pursuant to its charter, is responsible for reviewing company practices with respect to risk assessment and risk management. The audit committee works directly with

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members of senior management and the company’s internal audit staff to fulfill this responsibility and reports as appropriate to our board. Our board’s other committees also participate in risk oversight by considering risk aspects of matters within the scope of theiroftheir responsibilities.

Oversight of risk is also effected by our board as a whole in variousinvarious ways.

•The board reviews the structure and operation of various departments and functions of the company. In those reviews, the board discusses with management risks affecting those departments and functions and management’s approaches to mitigatingthose risks.

•The board reviews and approves each year’s operating plan and budget, and these reviews cover risks that could affect the plan and measures to cope withthose risks.

•In its review and approval of our Annual Reports on Form 10-K, the board reviews and discusses with management the company’s business and related risks, including as described in the “Business,” “Risk Factors” and “Management’s Discussion and Analysis” sections of the document. The audit committee conducts a similar process quarterly in connection with the preparation of Quarterly Reports onForm 10-Q.

•When the board reviews particular transactions and initiatives that require board approval as a legal matter, or that otherwise merit board involvement, the board generally includes related risk analysis and mitigation plans among the matters addressedwith management.

•The board or audit committee meet quarterly with our internal or external cybersecurity resources to review the efficacy of our cybersecurity risk initiatives and related policies and procedures. Lisa Troe, our audit committee chair, also has a certificate in cybersecurity oversight from the Software Engineering Institute at CarnegieMellon University.

The day-to-day identification and management of risk is the responsibility of the company’s management. As the market environment, industry practices, regulatory requirements, and the company’s business evolve, it is expected that management and our board will respond with appropriate adaptations to risk management andmanagementand oversight.

Our board believes that the process it has established to administer the board’s risk oversight function would be effective under a variety of leadership frameworks and, therefore, does not have a material effect on our choice of the board’s leadership structure described above under “Board Leadership“BoardLeadership Structure.”

Risk Assessment in Compensation Programs

The compensation committee annually assesses our executive and broad-based compensation and benefits programs on an overall basis to determine whether the programs’ provisions and operations create undesired or unintentional material risk.This risk assessment process takes into account numerous compensation terms and practices that we maintain that aid in controlling risk, including the mix of cash, equity, and near- and long-term incentive programs, the use of multi-year vesting periods for equity awards, and a variety of performance criteria for incentive compensation, the claw-back provisions that apply to our annual incentive cash plan and equity plan, and the cap on the maximum cash incentive awards that can be earned in a given year regardless of company performance. This risk assessment process also includes a review of program policies and practices, program analysis to identify risk and risk controls, and determinations as to the sufficiency of risk identification and risk control, the balance of potential risk to potential reward, and the significance of the programs and their risks to company strategy. Although the compensation committee reviews all significant compensation programs, it focuses on those programs with variable payout, in particular assessing the ability of participants to directly affect payouts, and the controlson such situations.

Based on the foregoing, we believe that our compensation policies and practices do not create risks that are reasonably likely to have a material adverse effect on the company as a whole. We also believe that our incentive compensation programs do not encourage risk-taking beyond the organization’s ability to effectively identify and manage significant risks; are compatible with effective internal controls and our risk-management practices; and are adequately supported by the compensation committee’s oversight of ourexecutive compensation programs.

Code of Business Conduct and Ethics

Our board of directors has adopted a Code of Business Conduct and Ethics that applies to each of our directors, officers and employees. The full text of our Code of Business Conduct and Ethics is posted on the “Corporate Governance” section of our Investor Relations website athttp://investor.rubiconproject.com. We intend to post any amendment to our Code of Business Conduct and Ethics, and any waivers of the Code for directors and executive officers, on the same website to the extent required by applicable law.rules adopted by the SEC and the New YorkStock Exchange.

Policy Against Hedging and Pledging

We recognize that hedging against losses in company shares may disturb the alignment between stockholders and employees that our equity awards are intended to build. Accordingly, we have incorporated prohibitions on various hedging activities within our Insider Trading Policy, which applies to directors, officers and othercertain employees who we have designated as insiders.insiders, as well as such persons’ family members, life partners, or owned or controlled entities. The policy prohibits all transactions that are designed to hedge or offset any decrease in the market value of our securities, including prepaid variable forward contracts, equity swaps, futures, collars, exchange funds, options, puts and callscalls. The policy also prohibits short sales of our securities and purchases or sales of puts or calls for speculativeforspeculative purposes.

Compensation Committee Interlocks and Insider Participation

Ms. Harden and Messrs. Coleman, Frankenberg, Mandal, and Spillane served on ourthe company’s compensation committee during the last completed fiscal year. Ms. Harden’s service on the compensation committee commenced in July 2019. Mr. Mandal’s service on the compensation committee ended with his resignation from the company’s board in May 2019. Mr. Coleman’s service on the compensation committee ended with his resignation from the company’s board of directors in April 2020 in connection with the effectiveness of our merger with Telaria. None of the members of ourthe compensation committee is or has at any time been an officer or employee of Rubicon Project. There are no interlocking relationships (and there were no such interlocking relationships during 2018)2019) between ourthe Rubicon Project board, of directors, executive officers or our compensation committee and the board of directors, executive officers or the compensation committee of anyand the Rubicon Project board, executive officers or the compensation committee ofany other company.

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DIRECTOR COMPENSATION

Each member of our board of directors who is not employed by us or any of our subsidiaries, referred to as a non-employee director, is compensated for service on our board through a combination of annual cash retainers and equity awards. For purposes of our director compensation program, a non-employee director is a member of theour board who is not, and has not been within the previous 180 days, either an employee of the companyours or any of itsour subsidiaries or a consultant performing material services to the companyus or any of itsour subsidiaries. In order to align the interests of non-employee directors and stockholders, equity awards constitute a majority of total directortotaldirector compensation.

Directors are reimbursed for travel, food, lodging and other expenses directly related to their activities as directors, such as attendance at board or committee meetings. Directors are also entitled to the protection provided by their indemnification agreements and the indemnification provisions in our certificate of incorporation and bylaws, and they receive coverage under a director and officer insurance policy that wethatwe maintain.

2020 Market Assessment and Post-Merger Compensation Program

In early 2020, in connection with the pending merger with Telaria, the Committee engaged Semler Brossy to perform a comprehensive review of non-employee director pay to ensure the programs were competitive and reflective of the larger, combined company going forward. Upon the close of the merger in April 2020, the following changes were made: the membership cash retainer was increased to $50,000 (from $30,000) and the Chairman retainer for Mr. Caine’s role as non-employee Chairman was established at an additional $50,000 for hisleadership role.

In April 2020, in connection with planned cost cutting initiatives, and to align with the CEO’s temporary reduction in base salary, the board member cash retainer was temporarily reduced by 30%.

Annual Cash Fees

Our non-employeeFor 2019, directors receivereceived annual cash retainer fees as described in the table below for board and committee service. Theservice.The fees are paid in four equal quarterly advance installments and prorated for any partial year of boardofboard service.

Equity Awards

Prior to changes to our non-employee director compensation program approved by(1)As noted above, effective April 1, 2020 the board in October 2018 that is effective formember cash retainer was increased to $50,000.

Equity Awards

For 2019, compensation, equity compensation for non-employee directors consisted of (i) an initial equity award with a calculated value of $450,000$375,000 for each newly-elected or appointed non-employee director, and (ii) annual awards with a calculated value of $225,000. In October 2018,$125,000. For 2019, equity awards for directors consisted solely of restricted stock units covering a number of shares determined by dividing the board reduced the initial award to have a calculated value of $375,000 and the annual award toby the closing price of a valueshare of $125,000 to bring the compensation back to medial levels in connection with making changes to the equity mix to eliminate theour common stock option component and remove the price floor, as further described below.

on thegrant date.

The initial equity award is granted on the date of appointment to the Boardboard or attainment of non-employee director status, unless the board or compensation committee specifyspecified another issuance date. Annual equity awards are issued on the date of each annual meeting or the date of attainment of non-employee director status. If no intervening annual meeting has been held, annual equity awards will be granted on a date specified by the compensation committee that is at least 30 calendar days after the first anniversary of the prior year’s annual meeting. The first annual award for non-employee directors who join the board at any time other than the date of an annual meeting is subject to proration for the partial year of service ending on the date of the next annualnextannual meeting.

Prior to the October 2018 amendments, each equity award consisted of stock options for a number of shares determined by dividing half of the calculated value of the award by the fair value of a single option on the grant date as determined for financial accounting purposes, and restricted stock units covering a number of shares determined by dividing half of the calculated value of the award by the closing price of a share of our common stock on the grant date. Stock options were granted with a per share exercise price equal to the closing price of a share of our common stock on the grant date. Notwithstanding the foregoing, if the closing price of our common stock was less than $12.00 on the grant date, then for stock options, $12.00 was used as the fair value of one share of common stock in the Black Scholes calculation used to determine the number of stock options to be granted,

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Initial equity awards vest, subject to continued board service, in three equal annual increments, on the first, second, and third anniversaries of the date of commencement of board service or attainment of non-employee director status or, if earlier, upon (but effective immediately prior to) the occurrence of a change in control of the company.Rubicon Project. Annual equity awards vest, subject to continued board service, on the first anniversary of the date of grant (or, if no intervening annual meeting has been held, annual equity awards will vest on the second anniversary of the prior year’s annual meeting) or, if earlier, upon the occurrence of either (1) a change in control of the companyRubicon Project (effective immediately prior thereto) or (2) the first regular annual meeting occurring in the year immediately following the year in which such annual equity awards were granted. In addition, if a non-employee director ceases board service for any reason other than removal for cause before vesting in full of equity awards, then the director’s awards vest with respect to a pro-rata portion of the underlying shares (up to but not exceeding the number of unvested shares remaining subject to such awards) determined based upon the period of board service. Vesting of equity awards will cease, and unvested equity awards will lapse, upon a recipient’s removal for cause from boardfromboard service.

Director Equity Retention Guidelines

Under equity retention guidelines implemented by the board in April 2016, each director is required to accumulate within five years from the later of the date the guidelines were implemented and the date of commencement of service for a new director, and thereafter to retain for the duration of board service, an amount of equity equal to five times the director’s base board cash compensation. Equity that counts toward the ownership requirement includes: (1) shares owned outright by the director or beneficially owned by the director by virtue of being held by a member of the director’s immediate family members residing in the same household or in a trust for the benefit of the director or his or her immediate family residing in the same household;(2) shares held in qualified plans or IRAs; (3) vested shares (or vested restricted stock units) deemed to be held in non-qualified plans;(4) the in-the-money portion of vested stock options (but not unvested stock options); and (5) unvested time-based restricted shares (orshares(or restricted stock units). Until the minimum level of company equity is achieved, a director is prohibited from selling or otherwise transferring beneficial ownership of more than one-half of: (a) the vested after-tax shares of our common stock obtained as a result of the vesting of any restricted stock or restricted stock unit award made after implementation of the equity retention guidelines; or (b) the shares of our common stock subject to the vested portion of any stock option award made after implementation of the equity retention guidelines, net of any shares surrendered or sold to cover exercise price and/or income tax resulting from thefromthe exercise.

20182019 Director Compensation Table

The following table sets forth all compensation provided to our non-employee directors for 2018.2019. The compensation for Mr. Barrett, our President and Chief Executive Officer, is described in the “Executive Compensation” section below. Mr. Barrett did not receive any compensation for his services as a director in 2018.directorin 2019.

14(1)Consists of annual board retainer and fees for service as a committee chair, committee member, or Lead Director, as the case may be. See the narrative disclosure above for a description ofsuch fees.

(2)In accordance with the rules of the SEC, these amounts represent the aggregate grant date fair value of the stock awards and option awards granted to the non-employee directors during the applicable fiscal year computed in accordance with ASC 718. Our equity awards valuation approach and related underlying assumptions for awards granted in 2019 are described in Note 2 “Organization and Summary of Significant Accounting Policies—Stock-Based Compensation” and Note 13 “Stock-Based Compensation” to the Consolidated Financial Statements inour Annual Report on Form 10-K (and the assumptions for awards granted prior to 2019 are set forth in the corresponding notes in the Annual Report on Form 10-K for the applicable fiscal year). The reported amounts do not necessarily reflect the value that may be realized by the executive with respect to the awards, which will depend on future changes in stock value and may be more or less than theamount shown.

(3)Stock awards consist of an annual award of 19,562 restricted stock units issued on May 15, 2019 to each director, other than Ms. Harden and Mr. Mandal, with an aggregate grant date fair market value as described in footnote 2 of $125,001. On February 15, 2019, Mr. Addante was granted a pro-rated annual equity award of 8,737 restricted stock units. On July 1, 2019, Ms. Harden was granted an initial equity award of 56,647 restricted stock units and a pro-rated annual equity award of 15,861 restricted stock units in connection with her appointment to the board. As of December 31, 2019, the aggregate number of shares of our common stock covered by unvested stock awards held by each of our non-employee directors wasas follows:

(4)As of December 31, 2019, the aggregate number of shares of our common stock covered by stock options held by each of our non-employee directors wasas follows:

(5)Mr. Addante became a non-employee director effective December27, 2018.

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PROPOSAL 2 — RATIFICATION OF THE SELECTION OF DELOITTE & TOUCHE LLP
AS INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The audit committee of our board of directors has selected Deloitte & Touche LLP (“Deloitte”) as our independent registered public accounting firm for the year ending December 31, 2019, and has further directed that management submit the selection of Deloitte as our independent registered public accounting firm for ratification by the stockholders at the annual meeting. Deloitte has served as our independent registered public accounting firm since 2018. PricewaterhouseCoopers LLP (“PwC”) previously served as our independent registered public accounting firm from 2012 to 2018. Although stockholder approval of the selection of Deloitte is not required by law, our board of directors believes it is advisable as a matter of good corporate governance to give stockholders an opportunity to ratify this selection. If this proposal is not ratified at the Annual Meeting, the audit committee may (but will not be required to) reconsider its selection of Deloitte. Even if the selection is ratified, the audit committee may in its discretion select a different independent registered public accounting firm at any time during the year if it determines that such a change would be appropriate.

Representatives of Deloitte are expected to be present at the Annual Meeting and will have the opportunity to make a statement if they desire to do so and will also be available to respond to appropriate questions from stockholders. Representatives of PwC are not expected to be present at the Annual Meeting.

The board of directors unanimously recommends that stockholders vote FOR the ratification of the selection of Deloitte as our independent registered public accounting firm.

Change of Independent Public Accounting Firm

As previously reported in our Current Report on Form 8-K, dated August 23, 2018 (the “Current Report”) and our 2018 proxy statement, the audit committee, with management’s assistance, conducted a competitive auditor review and selection process in order to select the firm to serve as our independent registered public accounting firm for the fiscal year ending December 31, 2018. The audit committee invited several firms to participate in this review process. As a result of this process, the audit committee made the decision to dismiss PwC as our independent registered public accounting firm on August 17, 2018, and informed PwC that they were dismissed on August 17, 2018.

PwC’s audit reports on the Company’s consolidated financial statements as of and for the fiscal years ended December 31, 2017 and 2016 did not contain any adverse opinions or disclaimers of opinion and were not qualified or modified as to uncertainty, audit scope or accounting principles.

During the fiscal years ended December 31, 2017 and 2016, there were (i) no disagreements between the company and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure, which disagreements, if not resolved(6)Ms. Harden was appointed to the satisfaction of PwC, would have caused PwC to make reference toBoard effective July1, 2019.

(7)Mr. Mandal resigned from the subject matter of the disagreement in their reports on our consolidated financial statements for such years, and (ii) no “reportable events” as that term is defined in Item 304(a)(1)(v) of Regulation S-K.Board effective May15, 2019.

We provided PwC with a copy of the disclosures we made in the Current Report prior to the time the Current Report was filed with the SEC. We requested that PwC furnish a letter addressed to the SEC stating whether or not it agrees with the statements made in the Current Report. A copy of PwC’s letter, dated August 23, 2018, was attached as Exhibit 16.1 to the Current Report and confirmed that they agreed with the statements we made in the Current Report.

On August 17, 2018, the audit committee appointed Deloitte as our independent registered public accounting firm for the fiscal year ending December 31, 2018. During the fiscal years ended December 31, 2017 and 2016, respectively, and the subsequent interim period through August 17, 2018, neither the company nor anyone acting on our behalf consulted with Deloitte on any of the matters or events set forth in Item 304(a)(2)(i) or 304(a)(2)(ii) of Regulation S-K.

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