We manufacture all of our semiconductor substrates using our proprietary vertical gradient freeze (VGF) technology. Most of our revenue is from sales of GaAs substrates. We manufacture all​

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All of our products are manufactured in the People's Republic of China (PRC or China), whichPRC by our PRC subsidiaries and PRC joint ventures. The PRC generally has favorable costs for facilities and labor compared with comparable facilities in the United States, Europe or Japan. We also have five joint venturesOur supply chain includes partial ownership of raw material companies in China that provide(subsidiaries/joint ventures). We believe this supply chain arrangement provides us with pricing advantages, reliable supply, market trend visibility and shorterbetter sourcing lead-times for key raw materials central to our final manufactured products. We consolidate, for accounting purposes, three of these joint ventures and have equity interests of 25% in each of the other two. We use our direct sales force in the United States and independent sales representatives in Europe and Asia to marketmanufacturing our substrates. Our ten largest customersraw material companies produce materials, including raw gallium (4N Ga), high purity gallium (6N and 7N Ga), starting material for 2010 were: Avago Technologies Trading Ltd., AZUR Space Solar Power GmbH, BeijingInP, arsenic, germanium, germanium dioxide, pyrolytic boron nitride (pBN) crucibles and boron oxide (B2O3). We have board representation in all of these raw material companies. We consolidate the companies in which we have either a controlling financial interest, or majority financial interest combined with the ability to exercise substantive control over the operations, or financial decisions, of such companies. We use the equity method to account for companies in which we have smaller financial interest and have the ability to exercise significant influence, but not control, over such companies. We purchase portions of the materials produced by these companies for our own use and they sell the remainder of their production to third parties.

Begun in 2017, the relocation of our gallium arsenide production lines is now completed. We entered into volume production in 2020. We transferred 100% of our ingot production to our new manufacturing facility in Kazuo, a city approximately 250 miles from Beijing. We transferred our wafer processing equipment for gallium arsenide to our new manufacturing facility in Dingxing, a city approximately 75 miles from Beijing. Our new facilities enabled us to expand capacity and upgrade some of our equipment. The new buildings are large enough that we can install additional equipment if market demand increases or if we gain market share. We also acquired sufficient land to enable us to add facilities, if needed in the future.

On November 16, 2020, we announced a strategic initiative to access China’s capital markets by beginning a process to list shares of Tongmei in an IPO on the STAR Market. To qualify for a STAR Market listing, the first major step in the process was to engage private equity firms in China Crystal Technology, Ltd., Hitachi Cable, Ltd.,(“Investors”) to invest funds in Tongmei. By December 31, 2020, 10 Investors had engaged with Tongmei for a total investment of approximately $48.1 million. (The currency used in the IQE group, Nan Da Guang Dang, Osram Opto Semiconductors GmbH,

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We are neither a PRC operating company nor do we conduct our operations in China through the use of VIEs. Accordingly, we do not require any permissions or approvals from the CSRC or other PRC government authorities to complete this offering of securities. Tongmei requires CSRC approval to complete its IPO on the STAR Market, which will not change the status of AXT as a U.S. public company. Recent statements and regulatory actions by China’s government on the use of VIEs and data security or anti-monopoly concerns have not impacted our ability to conduct our business or continue to list our common stock on the Nasdaq Global Select Market.

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The following organization chart depicts the consolidated structure as of June 30, 2021:

Dividends from within Our Corporate Structure

Occasionally, one of our PRC subsidiaries or PRC raw material joint ventures declares and pays a dividend. These dividends generally occur when the PRC joint venture declares a dividend for compound semiconductor substrates is expectedall of its shareholders. For the nine months ended September 30, 2021 and 2020, the aggregate dividends paid to increase, we believe that we are well-positionedus, directly or to leveragean intermediate entity within our PRC-based manufacturing capabilitiescorporate structure, by our PRC subsidiaries and accessPRC raw material joint ventures were approximately $774,000 and $0, respectively. In June 2021, AXT received a $774,000 dividend from one of our equity investments, Xiaoyi XingAn Gallium Co., Ltd. For the nine months ended September 30, 2021 and 2020, the aggregate dividends paid to favorably pricedminority shareholders by our PRC subsidiaries and PRC raw materialsmaterial joint ventures were approximately $0 and $89,000, respectively. All of these distributions were paid to increasethe PRC companies and the minority shareholders.

We have no current intentions to distribute to our market share.

Corporate Information

        AXT was incorporatedinvestors earnings under our corporate structure. We settle amounts owed under our transfer pricing arrangements in the ordinary course of business.

Dividends paid to the Company are subject to a 10% PRC withholding tax. The Company is required to obtain approval from the State Administration of Foreign Exchange (“SAFE”) to transfer funds in or out of the PRC. SAFE requires a valid agreement to approve the transfers, which are processed through a bank. There are no restrictions on the Company’s ability to transfer cash among its PRC subsidiaries. Other than PRC foreign exchange restrictions, the Company is not subject to any PRC restrictions and limitations on its ability to distribute earnings from its businesses, including its PRC subsidiaries and PRC joint ventures, to the Company and its investors as well as the ability to settle amounts owed by the Company to its PRC subsidiaries and PRC joint ventures.

Corporate Information

We were incorporated in California in December 1986 and reincorporated in the State of Delaware in May 1998. We changed our name from American Xtal Technology, Inc. to AXT, Inc. in July 2000. Our principal executive offices arecorporate office is located at 4281 Technology Drive, Fremont, California 94538, and theour telephone number at this address is (510) 683-5900.438-4700. We maintain a website at www.axt.com where general information about us is available. Our website, and the information contained therein, is not a part of this prospectus. The information that is contained on, or can be accessed through our website is not incorporated into this prospectus, and the inclusion of our website address is an inactive textual reference only.

The Securities WeThat May OfferBe Offered

We may offer up to $60,000,000 ofor sell common stock, preferred stock, depositary shares, warrants, debt securities, and/orwarrants, subscription rights, purchase contracts and units in one or more offerings and in any combination. This prospectus provides you with a general descriptionThe aggregate offering price of the securities we may offer. Asell pursuant to this prospectus supplement, whichwill not exceed $60,000,000. Each time securities are offered with this prospectus, we will provide each time we offer securities,a prospectus supplement that will describe the specific amounts, prices and terms of the securities being offered and the net proceeds we determineexpect to offer.receive from that sale.

The securities may be sold to or through underwriters, dealers or agents or directly to purchasers or as otherwise set forth in the section of this prospectus captioned “Plan of Distribution.” Each prospectus supplement will set forth the names of any underwriters, dealers, agents or other entities involved in the sale of securities described in that prospectus supplement and any applicable fee, commission or discount arrangements with them.

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Common Stock

We may offer shares of our common stock, par value $0.001 per share, either alone or underlying other registered securities convertible or exercisable into our common stock. Each holder of our common stock is entitled to one vote for each share on all matters to be voted upon by the stockholders. Holders of our common stock are entitled to receive ratably the dividends if any, as may be declared from time to time by our board of directors out of funds legally available therefor. If there is a liquidation, dissolution or winding up of our company, holders of our common stock would be entitled to share in our assets remaining afterfor the payment of liabilitiesdividends, subject to rights, if any, of preferred stockholders. We have not paid dividends in the past and any preferential rightshave no current plans to pay dividends. Each holder of any outstanding preferred stock.common stock is entitled to one vote per share. The holders of common stock have no preemptive rights. Currently, we do not pay a dividend and do not anticipate paying cash dividends in the foreseeable future.

Preferred Stock and Depositary Shares

        Under the terms of our amended and restated certificate of incorporation, ourOur board of directors is authorizedhas the authority, subject to limitations prescribed by Delaware law, to issue shares of preferred stock in one or more series, without stockholder approval. Our boardto establish from time to time the number of directors hasshares to be included in each series, and to fix the discretion to determinedesignation, powers, preferences and rights of the rights, preferences, privileges and restrictions, including voting rights, dividend rights, conversion rights, redemption privileges and liquidation preferences,shares of each series and any of preferred stock.

        We may also issue fractional shares of preferred stock that will be representedits qualifications, limitations or restrictions, in each case without further vote or action by depositary shares and depositary receipts.

our stockholders. Each series of preferred stock depositary shares or depositary receipts, if issued,offered by us will be more fully described in the particular prospectus supplement that will accompany this prospectus, including redemption provisions, rights in the event of our liquidation, dissolution or winding up, voting rights and rights to convert into common stock.

Depositary Shares

We have no present plans tomay issue any additionalfractional shares of preferred stock that will be represented by depositary shares and depositary receipts.

Each series of depositary shares or depositary receipts nor are any depositary shares or depositary receipts presently outstanding. As discussed below, as of April 29, 2011, there were 883,000 sharesoffered by us will be more fully described in the particular prospectus supplement that will accompany this prospectus, including redemption provisions, rights in the event of our series A preferred stock issuedliquidation, dissolution or winding up, voting rights and outstanding.

Table of Contents

RISK FACTORS
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Risk Factors

An investment in our securities involves a high degree of risk. We are subject to a number of unique legal and operational risks associated with our corporate structure, any of which could cause our stock price to decline. Please carefully read the informationin this section and included in “Item 1A – Risk Factors” of our most recent report on Form 10-K or 10-Q that is incorporated by reference in this prospectus before you invest in our securities. In particular, the following risk factors address issues associated with our corporate structure:

Although we are a Delaware corporation and are neither a PRC operating company nor do we conduct our operations in China through the use of VIEs, in the event we inadvertently concluded that we do not require any permissions or approvals from the CSRC or other PRC government authorities to complete this offering of securities or applicable laws, regulations, or interpretations change, we may be required to obtain such permissions or approvals to complete this offering of securities.

We are a Delaware corporation and are neither a PRC operating company nor do we conduct our operations in China through the use of VIEs. Accordingly, we do not require any permissions or approvals from the CSRC or other PRC government authorities to complete this offering of securities. In the event that we inadvertently concluded that such permission or approvals are not required or applicable laws, regulations, or interpretations change and we are required to obtain such permissions or approvals in the future and we fail to obtain such permissions or approvals, then we may not be able to complete this offering of securities. We may also be pressured to delist our securities, which would force the holders to sell these securities and could result in a material adverse effect on the value of these securities. We may face sanctions by the CSRC or other PRC government authorities for failure to obtain such permissions or approvals. These sanctions may include fines and penalties on our operations in China, limitations on our operating privileges in China, delays in or restrictions on the repatriation of the proceeds from this offering into the PRC, restrictions on or prohibition of the payments or remittance of dividends by our subsidiaries in China, or other actions that could have a material and adverse effect on our business, financial condition, results of operations, reputation and prospects, as well as the trading price of our common stock.

The PRC government may intervene in or influence our PRC operations at any time and the rules and regulations in China can change quickly with little advance notice. The PRC government may also exert more control over offerings conducted overseas and/or foreign investment in China-based issuers, which could result in a material change in our operations and/or the value of our common stock.

The PRC government is a single party form of government with virtually unlimited authority and power to intervene in or influence commercial operations in China. There are uncertainties regarding the enforcement by the PRC government of laws in China and the rules and regulations in China can change quickly with little advance notice. In the past, we have experienced such intervention or influence by the PRC government and a change in the rules and regulations in China when we were instructed by the Beijing municipal government to relocate our manufacturing facility in Beijing and expect that such intervention or influence or change in the rules and regulations in China could occur in the future. Any such intervention or influence or change in the rules and regulations in China could result in a material change in our PRC operations and/or the value of our common stock. The PRC government may also exert more control over offerings conducted overseas and/or foreign investment in China-based issuers, which could result in a material change in our operations and/or the value of our common stock. The PRC government may also seek to significantly limit or completely hinder our ability to offer or continue to offer our securities to investors and cause the value of such securities to significantly decline or be worthless.

Changes in China’s political, social, regulatory or economic environments may affect our financial performance.

Our financial performance may be affected by changes in China’s political, social, regulatory or economic environments. The role of the Chinese central and local governments in the Chinese economy is significant. The Beijing municipal government’s decision to move to the Tongzhou district, the original location of our manufacturing company, resulted in the city instructing virtually all existing manufacturing companies, including AXT, to relocate all or some of their manufacturing lines. We were instructed to move our gallium arsenide manufacturing line out of the area. Chinese policies toward hazardous materials, including arsenic, environmental controls, air pollution, economic liberalization, laws and policies affecting technology companies, foreign investment, currency exchange rates, taxation structure and other matters could change, resulting in greater restrictions on our ability to do business and operate our manufacturing facilities in China. We have observed a growing fluidity and tightening of regulations concerning hazardous materials, other environmental controls and air pollution. The Chinese government could revoke, terminate or suspend our operating licenses for reasons related to environmental control over the use of hazardous materials, air pollution, labor complaints, national security and similar reasons without compensation to us. Further, the central government encourages employees to report to the appropriate regulatory agencies possible safety or environmental violations, but there may not be actual violations. In days of severe air pollution the

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government has ordered manufacturing companies to stop all production. For example, in the first quarter of 2018, from February 27 to March 31, over 300 manufacturing companies, including us, were again intermittently shut down by the local government for a total of ten days due to severe air pollution. Our shipments were delayed and our revenue for the quarter was negatively impacted. We expect that mandatory factory shutdowns will occur in the future. Any failure on our part to comply with governmental regulations could result in the loss of our ability to manufacture our products. Further, any imposition of surcharges or any increase in Chinese tax rates or reduction or elimination of Chinese tax benefits could hurt our financial results.

Joint venture raw material companies in China bring certain risks.

Since our consolidated subsidiaries and all of our joint venture raw material companies reside in China, their activities could subject us to a number of risks associated with conducting operations internationally, including:

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Risks exist in utilizing our new gallium arsenide manufacturing sites efficiently.

The Chinese government has imposed, and may impose in the future, manufacturing restrictions and regulations that require us to move part of our manufacturing operations to a different location or temporarily cease or limit manufacturing. Such relocation, or other restrictions on manufacturing, could materially and adversely impact our results of operations and our financial condition.

The Beijing city government is moving its offices to the Tongzhou district where our original manufacturing facility is currently located. The city government is in the process of moving thousands of government employees into this area. To create room and upgrade the district, the city instructed virtually all existing manufacturing companies, including AXT, to relocate all or some of their manufacturing lines. We were instructed to move our gallium arsenide manufacturing line out of the area.

Although the relocation is completed and we are in volume production at the new sites, unforeseen manufacturing issues at the new sites could still occur. Problems could occur as we add capacity or comply with strict guidelines as customers perform their qualifications. All of this will require us to continue to diligently address the many details that arise at both of the new sites. A failure to properly accomplish this could result in disruption to our production and have a material adverse impact on our revenue, our results of operations and our financial condition. If we fail to meet the product qualification and volume requirements of a customer, we may lose sales to that customer. Our reputation may also be damaged. Any loss of sales could have a material adverse effect on our revenue, our results of operations and our financial condition.

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Some of our key employees are relocating to our new manufacturing sites. Travel restrictions within China resulting from COVID-19 have impacted their relocation and hindered commuting. Certain employees may choose not to relocate. If we are unable to continue to employ those key employees in our original manufacturing facility, we may be required to terminate those employees and could incur severance costs. If the Chinese government does not assist us in this matter it could materially and adversely impact our results of operations and our financial condition. Further, a loss of key employees or our inability to hire qualified employees could disrupt our production, which could materially and adversely impact our results of operations and our financial condition.

The Chinese government has in the past imposed temporary restrictions on manufacturing facilities, such as the restrictions imposed on polluting factories for the 2008 Olympics and the 2014 Asian Pacific Economic Cooperation event. These restrictions included a shutdown of the transportation of materials and power plants to reduce air pollution. To reduce air pollution in Beijing, the Chinese government has sometimes limited the construction of new, or expansion of existing, facilities by manufacturing companies in the Beijing area or required mandatory factory shutdowns. For example, in the first quarter of 2018, over 300 manufacturing companies, including AXT, were intermittently shut down by the local government for a total of ten days from February 27 to March 31 due to severe air pollution. If the government applies similar restrictions to us or requires mandatory factory shutdowns in the future, then such restrictions or shutdowns could have an adverse impact on our results of operations and our financial condition. Our ability to supply current or new orders could be significantly impacted. Customers could then be required to purchase products from our competitors, causing our competitors to take market share from us.

In addition, from time to time, the Chinese government issues new regulations, which may require additional actions on our part to comply. On February 27, 2015, the China State Administration of Work Safety updated its list of hazardous substances. The previous list, which was published in 2002, did not restrict the materials that we use in our wafers. The new list added gallium arsenide. As a result of the newly published list, we were required to seek additional permits.

The Chinese central government is increasingly aware of air pollution and other forms of environmental pollution and their reform efforts can impact our manufacturing, including intermittent mandatory shutdowns.

The Chinese central government is demonstrating strong leadership to improve air quality and reduce environmental pollution. These efforts have impacted manufacturing companies through mandatory shutdowns, increased inspections and regulatory reforms. In the fourth quarter of 2017, many manufacturing companies in the greater Beijing area, including AXT, were instructed by the local government to cease most manufacturing for several days until the air quality improved. In the first quarter of 2018, from February 27 to March 31 over 300 manufacturing companies, including AXT, were again intermittently shut down by the local government for a total of ten days, or 30 percent of the remaining calendar days, due to severe air pollution. Our shipments were delayed and our revenue for the quarter was negatively impacted. We expect that mandatory factory shutdowns will occur in the future. If the frequency of such shutdowns increases, especially at the end of a quarter, or if the total number of days of shutdowns prevents us from producing enough wafers to ship, then these shutdowns will have a material adverse effect on our manufacturing output, revenue and factory utilization. Each of our raw material supply chain companies could also be impacted by environmental related orders from the central government.

Shutdowns or underutilizing our manufacturing facilities may result in declines in our gross margins.

An important factor in our success is the extent to which we are able to utilize the available capacity in our manufacturing facilities. A number of factors and circumstances may reduce utilization rates, including periods of industry overcapacity, low levels of customer orders, operating inefficiencies, mechanical failures and disruption of operations due to expansion, power interruptions, fire, flood, other natural disasters or calamities or government-ordered mandatory factory shutdowns, including as a result of the COVID-19 pandemic. Severe air pollution in Beijing can trigger mandatory factory shutdowns. For example, in the first quarter of 2018, over 300 manufacturing companies, including AXT, were intermittently shut down by the local government for a total of ten days from February 27 to March 31, due to severe air pollution. Further, we have increased capacity by adding two new sites and this could reduce our utilization rate and increase our depreciation charges. Because many portions of our manufacturing costs are relatively fixed, high utilization rates are critical to our gross margins and operating results. If we fail to achieve acceptable manufacturing volumes or experience product shipment delays, our results of operations will be negatively affected. During periods of decreased demand, we have underutilized our manufacturing lines. If we are unable to improve utilization levels at our facilities during periods of decreased demand and correctly manage capacity, the fixed expense levels will have an adverse effect on our business, financial condition and results of operations. For example, in the three months ended December 31, 2019, our revenue dropped to $18.4 million and our gross margin was only 21.0%.

If we are unable to utilize the available capacity in our manufacturing facilities, we may need to implement a restructuring plan, which could have a material adverse effect on our revenue, our results of operations and our financial condition. For example, in 2013, we concluded that incoming orders were insufficient and that we were significantly

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underutilizing our factory capacity. As a result, in February 2014, we announced a restructuring plan with respect to our wafer manufacturing company, Tongmei, in order to better align manufacturing capacity with demand. Under the restructuring plan, we recorded a charge of approximately $907,000 in the first quarter of 2014.

If we receive fewer customer orders than forecasted or if our customers delay or cancel orders, we may not be able to reduce our manufacturing costs in the short-term and our gross margins would be negatively affected. In addition, lead times required by our customers are shrinking, which reduces our ability to forecast orders and properly balance our capacity utilization.

Enhanced trade tariffs, import restrictions, export restrictions, Chinese regulations or other trade barriers may materially harm our business.

All of our wafer substrates are manufactured in China and in the years 2020 and 2019, approximately 10% of our revenue was generated by sales to customers in North America, primarily in the U.S. In September 2018, the Trump Administration announced a list of thousands of categories of goods that became subject to tariffs when imported into the United States. This pronouncement imposed tariffs on wafer substrates we imported into the United States. The initial tariff rate was 10% and subsequently was increased to 25%. In the years 2020 and 2019 we paid approximately $1.3 million and $0.7 million, respectively, in tariffs. The future impact of tariffs and trade wars is uncertain. We may be required to raise prices, which may result in the loss of customers and our business, financial condition and results of operations may be materially harmed. Additionally, it is possible that our business could be adversely impacted by retaliatory trade measures taken by China or other countries in response to existing or future tariffs, which could cause us to raise prices or make changes to our operations, which could materially harm our business, financial condition and results of operations.

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The economic and political conditions between China and the United States, in our view, create an unstable business environment. The United States government has restricted access by certain Chinese technology companies to items produced domestically and abroad from U.S. technology and software, which may impact our ability to grow our revenue. Trade restrictions against China have resulted in a greater determination within China to be self-sufficient and produce more goods domestically. Government agencies in China may be encouraging and supporting the founding of new companies, the addition of new products in existing companies and more vertical integration within companies. These factors have resulted in lower revenue from sales of our wafer substrates in China. Further, the continued threats of tariffs and other trade restrictions could have a generally disruptive impact on the global economy and, therefore, negatively impact our sales.

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In addition, we may incur increases in costs and other adverse business consequences, including loss of revenue or decreased gross margins, due to changes in tariffs, import or export restrictions, further trade barriers, or unexpected changes in regulatory requirements. For example, in July 2012, we received notice of retroactive value-added taxes (VATs) levied by the tax authorities in China, which applied for the period from July 1, 2011 to June 30, 2012. We expensed the retroactive VATs of approximately $1.3 million in the quarter ended June 30, 2012, which resulted in a decrease in our gross margins. These VATs will continue to negatively impact our gross margins for the future quarters. Given the relatively fluid regulatory environment in China and the United States, there could be additional tax or other regulatory changes in the future. Any such changes could directly and materially adversely impact our financial results and general business condition.

If China places restrictions on freight and transportation routes and on ports of entry and departure this could result in shipping delays or increased costs for shipping.

In August 2015, there was an explosion at the Port of Tianjin, China. As a result of this incident the government placed restrictions on importing certain materials and on freight routes used to transport these materials. We experienced some modest disruption from these restrictions. If the government were to place additional restrictions on the transportation of materials, then our ability to transport our raw materials or products could be limited and result in manufacturing delays or bottlenecks at shipping ports, affecting our ability to deliver products to our customers. During periods of such restrictions, we may increase our stock of critical materials (such as arsenic, gallium and other items) for use during the period that these restrictions are likely to last, which will increase our use of cash and increase our inventory level. Any of these restrictions could materially and adversely impact our results of operations and our financial condition.

Our international operations are exposed to potential adverse tax consequence in China.

Our international operations create a risk of potential adverse tax consequences. Taxes on income in our China-based companies are dependent upon acceptance of our operational practices and intercompany transfer pricing by local tax authorities as being on an arm's length basis. Due to inconsistencies among taxing authorities in application of the arm's length standard, transfer pricing challenges by tax authorities could, if successful, materially increase our consolidated income tax expense. We are subject to tax audits in China and an audit could result in the assessment of additional income tax against us. This could have a material adverse effect on our operating results or cash flows in the period or periods for which that

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determination is made and could result in increases to our overall tax expense in subsequent periods. Various taxing agencies in China are increasingly focused on tax reform and other legislative action to increase tax revenue. In addition to risks regarding income tax we have in the past been retroactively assessed value added taxes (“VAT” or sales tax) and such VAT assessments could occur again in the future.

We derive a significant portion of our revenue from international sales, and our ability to sustain and increase our international sales involves significant risks.

Approximately 90% of our revenue is from international sales. We expect that sales to customers outside the United States, particularly sales to customers in Japan, Taiwan, Europe and China, will continue to represent a significant portion of our revenue. Therefore, our revenue growth depends significantly on the expansion of our international sales and operations.

All of our manufacturing facilities and most of our suppliers are also located outside the United States. Managing our overseas operations presents challenges, including periodic regional economic downturns, trade balance issues, threats of trade wars, varying business conditions and demands, political instability, variations in enforcement of intellectual property and contract rights in different jurisdictions, differences in the ability to develop relationships with suppliers and other local businesses, changes in U.S. and international laws and regulations, including U.S. export restrictions, fluctuations in interest and currency exchange rates, the ability to provide sufficient levels of technical support in different locations, cultural differences and perceptions of U.S. companies, shipping delays and terrorist acts or acts of war, natural disasters and epidemics or pandemics, such as COVID-19, among other risks. Many of these challenges are present in China, which represents a large potential market for semiconductor devices. Global uncertainties with respect to: (i) economic growth rates in various countries; (ii) sustainability of demand for electronic products; (iii) capital spending by semiconductor manufacturers; (iv) price weakness for certain semiconductor devices; (v) changing and tightening environmental regulations; (vi) political instability in regions where we have operations and (vii) trade wars may also affect our business, financial condition and results of operations.

Our dependence on international sales involves a number of risks, including:

Most of our sales are denominated in U.S. dollars, except for sales to our Chinese customers which are denominated in renminbi and our Japanese customers which are denominated in Japanese yen. We also have some small sales denominated in Euro. Increases in the value of the U.S. dollar could increase the price of our products in non-U.S. markets and make our products more expensive than competitors’ products in these markets.

The terms of the private equity raised in China as a first step toward an IPO on the STAR Market grant each investor a right of redemption if Tongmei fails to achieve its IPO.

Pursuant to the Capital Investment Agreements with the Investors, each Investor has the right to require AXT to redeem any or all Tongmei shares held by such Investor at the original purchase price paid by such Investor, without interest, in the event of a material adverse change or if Tongmei does not achieve its IPO on or before December 31, 2022. This right is suspended when Tongmei submits its formal application to the CSRC. On January 10, 2022, the Shanghai Stock Exchange accepted for review the formal application of Tongmei to list its shares in an IPO on the STAR Market. If the Shanghai Stock Exchange approves the formal application, then the Shanghai Stock Exchange will forward it to the CSRC for review. However, if on December 31, 2022 the IPO application has been submitted and accepted by the CSRC or the stock exchange and such submission remains under review, then the date when such investor is entitled to exercise such redemption right shall be deferred to a date when such submission is rejected by the CSRC or stock exchange, or the date when Tongmei withdraws its IPO application. The process of going public on the STAR Market includes several periods of review and is therefore a lengthy process. Tongmei does not expect to complete the IPO until mid-2022. The listing of Tongmei on China’s STAR

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Market will not change the status of AXT as a U.S. public company. There can be no assurances that Tongmei will complete its IPO by December 31, 2022 or at all. In the event that investors exercise their redemption rights, we may be required to seek additional capital in order to redeem their Tongmei shares and there would be no assurances that such capital would be available on terms acceptable to us, if at all. Any redemptions could have a material adverse effect on our business, financial condition and results of operations.

We are subject to foreign exchange gains and losses that materially impact our income statement.

We are subject to foreign exchange gains and losses that may materially impact our statement of operations. For example, in 2020 we incurred a loss of $411,000.

The functional currency of our companies in China is the Chinese renminbi, the local currency. We can incur foreign exchange gains or losses when we pay dollars to one of our China-based companies or a third-party supplier in China. Similarly, if a company in China pays renminbi into one of our bank accounts transacting in dollars the renminbi will be converted to dollars and we can incur a foreign exchange gain or loss. Hedging renminbi will be considered in the future but it is complicated by the number of companies involved, the diversity of transactions and restrictions imposed by the banking system in China.

Sales to Japanese customers are denominated in Japanese yen. This subjects us to fluctuations in the exchange rates between the U.S. dollar and the Japanese yen and can result in foreign exchange gains and losses. This has been problematic in the past and, therefore, we instituted a foreign currency hedging program dealing with yen which has mitigated the problem.

Although the audit report incorporated by reference in this prospectus is prepared by an independent registered public accounting firm that is currently inspected fully by the PCAOB, there is no guarantee that future audit reports will be prepared by an independent registered public accounting firm that is completely inspected by the PCAOB.

Our independent registered public accounting firm, BPM, is registered with the PCAOB and is subject to regular inspections by the PCAOB to assess its compliance with the applicable professional standards. Although we have operations in China, a jurisdiction where the PCAOB is currently unable to conduct inspections without the approval of the Chinese government authorities, our independent registered public accounting firm is currently inspected fully by the PCAOB.

Inspections of other independent registered public accounting firms conducted by the PCAOB outside China have at times identified deficiencies in those independent registered public accounting firms’ audit procedures and quality control procedures, which may be addressed as part of the inspection process to improve future audit quality. The lack of PCAOB inspections of audit work undertaken in China prevents the PCAOB from regularly evaluating independent registered public accounting firms’ audits and their quality control procedures. As a result, to the extent that any of our independent registered public accounting firm’s work papers are or become located in China, such work papers may not be subject to inspection by the PCAOB. As a result, investors would be deprived of such PCAOB inspections, which could result in limitations or restrictions to our access of the U.S. capital markets.

As part of a continued regulatory focus in the United States on access to audit and other information currently protected by national law, in particular PRC laws, in June 2019, a bipartisan group of lawmakers introduced bills in both houses of the U.S. Congress which, if passed, would require the SEC to maintain a list of issuers for which PCAOB is not able to inspect or investigate the audit work performed by a non-U.S. independent registered public accounting firm completely. The proposed Ensuring Quality Information and Transparency for Abroad-Based Listings on our Exchanges Act prescribes increased disclosure requirements for these issuers and, beginning in 2025, the delisting from U.S. national securities exchanges such as the Nasdaq Global Select Market of issuers included on the SEC’s list for three consecutive years. It is unclear if this proposed legislation will be enacted. Furthermore, there have been recent deliberations within the U.S. government regarding potentially limiting or restricting companies based in China from accessing U.S. capital markets. On May 20, 2020, the U.S. Senate passed the Holding Foreign Companies Accountable Act (the “HFCA Act”), which includes requirements for the SEC to identify issuers whose audit work is performed by independent registered public accounting firms that the PCAOB is unable to inspect or investigate completely because of a restriction imposed by a non-U.S. authority in the independent registered public accounting firm’s local jurisdiction. The U.S. House of Representatives passed the HFCA Act on December 2, 2020, and the HFCA Act was signed into law on December 18, 2020. Additionally, in July 2020, the U.S. President’s Working Group on Financial Markets issued recommendations for actions that can be taken by the executive branch, the SEC, the PCAOB or other federal agencies and department with respect to Chinese companies listed on U.S. stock exchanges and their independent registered public accounting firms, in an effort to protect investors in the United States. In response, on November 23, 2020, the SEC issued guidance highlighting certain risks (and their implications to U.S. investors) associated with investments in issuers based in China and summarizing enhanced disclosures the SEC recommends issuers based in China make regarding such risks. On March 24, 2021, the SEC adopted interim final rules relating to the implementation of certain disclosure and documentation requirements of the HFCA Act. We will be required to comply with

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these rules if the SEC identifies us as having a “non-inspection” year (as defined in the interim final rules) under a process to be subsequently established by the SEC. The SEC is assessing how to implement other requirements of the HFCA Act, including the listing and trading prohibition requirements described above. Under the HFCA Act, our securities may be prohibited from trading on the Nasdaq Global Select Market or other U.S. stock exchanges if our independent registered public accounting firm is not inspected by the PCAOB for three consecutive years, and this ultimately could result in our common stock being delisted. Furthermore, on June 22, 2021, the U.S. Senate passed the Accelerating Holding Foreign Companies Accountable Act, which, if enacted, would amend the HFCA Act and require the SEC to prohibit an issuer’s securities from trading on any U.S. stock exchanges if its independent registered public accounting firm is not subject to PCAOB inspections for two consecutive years instead of three. On September 22, 2021, the PCAOB adopted a final rule implementing the HFCA Act, which provides a framework for the PCAOB to use when determining, as contemplated under the HFCA Act, whether the PCAOB is unable to inspect or investigate completely independent registered public accounting firms located in a non-U.S. jurisdiction because of a position taken by one or more authorities in that jurisdiction and was approved by the SEC on November 5, 2021.

​

While we believe that there has been dialogue among the CSRC, the SEC and the PCAOB regarding the inspection of PCAOB-independent registered public accounting firms in China, there can be no assurance that we will be able to comply with requirements imposed by U.S. regulators. Delisting of our common stock would force holders of our common stock to sell their shares. The market price of our common stock could be adversely affected as a result of anticipated negative impacts of these executive or legislative actions upon, as well as negative investor sentiment towards, companies with operations in China that are listed in the United States, regardless of whether these executive or legislative actions are implemented and regardless of our actual operating performance.

The prospectus supplement applicable to each offering of our securities will contain a discussion of the risks applicable to an investment in our securities. Prior to making a decision about investing in our securities, you should carefully consider the specific factors discussed under the heading "Risk Factors"section in the applicable prospectus supplement captioned “Risk Factors,” together with all of the other information contained or incorporated by reference in the prospectus supplement or appearing or incorporated by reference in this prospectus. You should also consider the risks, uncertainties and assumptions discussed under “Part I—Item 1A, "Risk Factors," in1A—Risk Factors” of our most recent Annual Report on Form 10-K for the fiscal year ended December 31, 2010 and any updates describedin “Part II—Item 1A—Risk Factors” in our most recent Quarterly ReportsReport on Form 10-Q all of whichfiled subsequent to such Form 10-K that are incorporated herein by reference, andas may be amended, supplemented or superseded from time to time by other reports we file with the SEC in the future and any prospectus supplement related to a particular offering.future. The risks and uncertainties we have described are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our operations. The occurrence

PRC Cybersecurity

We are neither a PRC operating company nor do we conduct our operations in China through the use of any of these known or unknown risks might cause you to lose all or part of your investmentVIEs. We do not have direct operations in the offered securities.PRC. Accordingly, we do not believe we are subject to oversight by the Cyberspace Administration of China (the “CAC”) regarding data security. Except for routine personal information necessary to process payroll and other benefits and emergency contact information, our PRC subsidiaries and PRC joint ventures do not collect or maintain personal information. We believe our PRC subsidiaries and PRC joint ventures are in material compliance with the regulations or policies that have been issued by the CAC as of the date of this prospectus.

Forward-Looking Statements
FORWARD-LOOKING STATEMENTS

This prospectus, each prospectus supplement and the information incorporated by reference in this prospectus and each prospectus supplement contain certain statements that constitute "forward-looking statements"“forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934.1934, as amended, or the Exchange Act. Statements regarding completing steps in connection with the proposed listing of shares of Tongmei on the STAR Market, being accepted to list shares of Tongmei on the STAR Market and the timing and completion of such listing of shares of Tongmei on the STAR Market are forward-looking statements. The words "anticipate," "expect," "believe," "goal," "plan," "intend," "estimate," "may," "will,"“believe,” “may,” “will,” “estimate,” “continue,” “anticipate,” “intend,” “expect,” “could,” “would,” “project,” “plan,” “potentially,” “likely,” and similar expressions and variations thereof are intended to identify forward-looking statements, but are not the exclusive means of identifying such statements. Those statements appear in this prospectus, any accompanying prospectus supplement and the documents incorporated herein and therein by reference, particularly in the sections entitled "Prospectus Summary," "Risk Factors," "Management'scaptioned “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations" and "Business,"Operations” and include statements regarding the intent, belief or current expectations of the company andour management that are subject to known and unknown risks, uncertainties and assumptionsassumptions. These risks, uncertainties and other factors that could cause actual results and the timing of certain events to differ materially from future results expressed or implied by such forward-looking statements. Factors that could cause or contribute to such differencesassumptions include, but are not limited to, those discussedthe withdrawal, cancellations or requests for redemptions by private equity funds in China of their investments in Tongmei, the administrative challenges in satisfying the requirements of various government agencies in China in connection with the investments in Tongmei and the listing of shares of Tongmei on the STAR Market, continued open access to companies to list shares on the STAR Market, investor enthusiasm for new listings of shares on the STAR Market, geopolitical tensions between China and

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the United States, and other factors described in the section titled "Risk Factors" set forth above.

        This prospectus, any prospectus supplement and the information incorporated by reference inof this prospectus andcaptioned “Risk Factors.” You are cautioned that any prospectus supplement also contain statements that are based on management's current expectations and beliefs, including estimates and projections about our company, industry, financial condition, results of operations and other matters. Thesesuch forward-looking statements are not guarantees of future performance and are subject to numerousinvolve risks and uncertainties, and assumptions that are difficult to predict.actual results may differ materially from those projected in the forward-looking statements as a result of various factors.

Because forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified, you should not rely upon forward-looking statements as predictions of future events. The events and circumstances reflected in the forward-looking statements may not be achieved or occur and actual results could differ materially from those projected in the forward-looking statements. Except as required by applicable law, including the securities laws of the United States and the rules and regulations of the SEC, we do not plan to publicly update or revise any forward-looking statements contained herein after we distribute this prospectus, whether as a result of any new information, future events or otherwise.

TableIn addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of Contents

RATIO OF EARNINGS TO FIXED CHARGES

        The following table sets forth our ratiothe date of earnings to fixed charges onthis prospectus, and although we believe such information forms a historicalreasonable basis for eachsuch statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted a thorough inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.

This prospectus and the periods indicated. You should read these ratios in connection with our consolidated financial statements, including the notes to those statements,documents incorporated by reference in this prospectus.

prospectus may contain market data that we obtain from industry sources. These sources do not guarantee the accuracy or completeness of the information. Although we believe that our industry sources are reliable, we do not independently verify the information. The ratio of earnings to fixed charges has been computedmarket data may include projections that are based on a consolidated basis. "Earnings" consistnumber of income or loss from continuing operations before income taxes plus fixed charges. Fixed charges consist of interest expenseother projections. While we believe these assumptions to be reasonable and an estimatesound as of the interest componentdate of rent expense.this prospectus, actual results may differ from the projections.

USE OF PROCEEDS
Use of Proceeds

We will retain broad discretion over the use of the net proceeds to us from the sale of our securities under this prospectus. Unless otherwise indicatedprovided in the applicable prospectus supplement, we willcurrently expect to use the net proceeds that we receive from the sale of securities offered by this prospectusoffering for general corporate purposes, which may include working capital, capital expenditures and other general corporate expenses and acquisitionspurposes. We may also use a portion of the net proceeds to acquire, license or invest in complementary products, technologies or businesses. The timing and amountexpected use of net proceeds of this offering represents our actual expenditures will becurrent intentions based on many factors, including cash flows from operationsour present plans and business conditions. We cannot specify with certainty all of the anticipated growth of our business. As a result, unless otherwise indicated in the prospectus supplement, our management will have broad discretion to allocateparticular uses for the net proceeds to be received upon the closing of the offerings.this offering. Pending their ultimate use,these uses, we intendplan to invest the net proceeds of this offering in short-term,short- and intermediate-term, interest-bearing obligations, investment-grade interest-bearing instruments.instruments, certificates of deposit or direct or guaranteed obligations of the U.S. government.

Description of Capital Stock

Table of Contents

DESCRIPTION OF CAPITAL STOCK

The following information describes our common stock and preferred stock, as well as certain provisionsdescription of our amended and restated certificate of incorporation and bylaws. This descriptioncapital stock is only a summary. You should also referincorporated by reference to Exhibit 4.1 to our certificate of incorporation and bylaws, which have beenAnnual Report on Form 10-K for the fiscal year ended December 31, 2020, filed with the SEC on March 23, 2021.

Description of Debt Securities

The following description, together with the additional information we include in any applicable prospectus supplement, summarizes certain general terms and provisions of the debt securities that we may offer under this prospectus. When we offer to sell a particular series of debt securities, we will describe the specific terms of the series in a supplement to this prospectus. We will also indicate in the supplement to what extent the general terms and provisions described in this prospectus apply to a particular series of debt securities.

We may issue debt securities either separately, or together with, or upon the conversion or exercise of or in exchange for, other securities described in this prospectus. Debt securities may be our senior, senior subordinated or subordinated obligations and, unless otherwise specified in a supplement to this prospectus, the debt securities will be our direct, unsecured obligations and may be issued in one or more series.

The debt securities will be issued under an indenture between us and a trustee to be identified in an accompanying prospectus supplement. We have summarized select portions of the indenture below. The summary is not complete. The form of the indenture has been filed as exhibitsan exhibit to ourthe registration statement of which this prospectus forms a part.

General

        Our authorized capital stock consists of 70,000,000 shares of common stock with a $0.001 par value per share,part and 2,000,000 shares of preferred stock with a $0.001 par value per share, 1,000,000 shares of which are designated as "Series A Preferred Stock". Our board of directorsyou should read the indenture for provisions that may establishbe important to you. In the rights and preferencessummary below, we have included references to the section numbers of the preferred stock from time to time. As of April 29, 2011, there were 31,973,288 shares of common stock issued and outstanding and there were 883,000 shares of our series A preferred stock issued and outstanding.

        The following is a summary of the material provisions of the common stock and preferred stock provided for in our amended and restated certificate of incorporation and bylaws. For additional detail about our capital stock, please refer to our certificate of incorporation and bylaws, each as amended.

Common Stock

        Each holder of our common stock is entitled to one vote for each share on all matters to be voted upon by the stockholders. Subject to any preferential rights of any outstanding preferred stock, holders of our common stock are entitled to receive ratably the dividends, if any, as may be declared from time to time by the board of directors out of funds legally available therefore. We have never declared or paid any cash dividend on our capital stock and do not anticipate paying any cash dividendsindenture so that you can easily locate these provisions. Capitalized terms used in the foreseeable future. If there is a liquidation, dissolution or winding upsummary and not defined herein have the meanings specified in the indenture.

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General

The terms of our company, holders of our common stock would be entitled to share in our assets remaining after the payment of liabilities and any preferential rights of any outstanding preferred stock.

        Holders of our common stock have no preemptive or conversion rights or other subscription rights, and there are no redemption or sinking fund provisions applicable to the common stock. The outstanding shares of common stock are fully paid and non-assessable. The rights, preferences and privileges of the holders of our common stock are subject to, and may be adversely affected by, the rights of the holders of shares of anyeach series of preferred stock that we may designate and issue in the future.

        Our common stock is listed on the NASDAQ Global Select Market under the symbol "AXTI." The transfer agent and registrar for the common stock is Registrar and Transfer Company. Its address is 10 Commerce Drive, Cranford, NJ 07016, and its telephone number is (800) 368-5948.

Preferred Stock

        Our amended and restated certificatedebt securities will be established by or pursuant to a resolution of incorporation provides that we may issue up to 2,000,000 shares of preferred stock, $0.001 par value per share, or preferred stock. As of March 31, 2011, 883,000 shares of our series A preferred stock were issued and outstanding and are non-voting and non-convertible preferred stock with a 5.0% cumulative annual dividend rate payable when declared by the board of directors and $4 per share liquidation preference over common stock, and must be paid before any distribution is made to common stockholders. Other thanset forth or determined in the series A preferred stock, no sharesmanner provided in a resolution of preferred stock are currently outstanding.

our board of directors, in an officer’s certificate or by a supplemental indenture. The following description of preferred stock and the description of theparticular terms of any particulareach series of preferred stockdebt securities will be described in a prospectus supplement relating to such series (including any pricing supplement or term sheet).

We can issue an unlimited amount of debt securities under the indenture that we choose to issue hereunder and thatmay be in one or more series with the same or various maturities, at par, at a premium, or at a discount. We will be set forth in the relateda prospectus supplement are not complete. These descriptions are qualified in their entirety by reference

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We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture. We will provide you with information on the federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

If we denominate the purchase price of any of the debt securities in a foreign currency or currencies or a foreign currency unit or units, or if the principal of and any premium and interest on any series of debt securities is payable in a foreign currency or currencies or a foreign currency unit or units, we will provide you with information on the restrictions, elections, general tax considerations, specific terms and other information with respect to that issue of debt securities and such foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Transfer and Exchange

Each debt security will be represented by either one or more global securities registered in the name of a clearing agency registered under the Exchange Act, which we refer to as the depositary, or a nominee of the depositary (we will refer to any debt security represented by a global debt security as a “book-entry debt security”), or a certificate issued in definitive registered form (we will refer to any debt security represented by a certificated security as a “certificated debt security”) as set forth in the applicable prospectus supplement. Except as set forth under the heading “Global Debt Securities and Book-Entry System” below, book-entry debt securities will not be issuable in certificated form.

Certificated Debt Securities

You may transfer or exchange certificated debt securities at any office we maintain for this purpose in accordance with the terms of the indenture. No service charge will be made for any transfer or exchange of certificated debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with a transfer or exchange.

You may effect the transfer of certificated debt securities and the right to receive the principal of, premium and interest on certificated debt securities only by surrendering the certificate representing those certificated debt securities and either reissuance by us or the trustee of the certificate to the new holder or the issuance by us or the trustee of a new certificate to the new holder.

Global Debt Securities and Book-Entry System

Each global debt security representing book-entry debt securities will be deposited with, or on behalf of, the depositary, and registered in the name of the depositary or a nominee of the depositary.

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Covenants

We will set forth in the applicable prospectus supplement any restrictive covenants applicable to any issue of debt securities.

No Protection in the Event of a Change of Control

Unless we state otherwise in the applicable prospectus supplement, the debt securities will not contain any provisions which may afford holders of the debt securities protection in the event we have a change in control or in the event of a highly leveraged transaction (whether or not such transaction results in a change in control) which could adversely affect holders of debt securities.

Consolidation, Merger and Sale of Assets

We may not consolidate with or merge with or into, or convey, transfer or lease all or substantially all of our properties and assets to any person, which we refer to as a successor person, unless:

Notwithstanding the above, any of our subsidiaries may consolidate with, merge into or transfer all or part of its properties to us.

Events of Default

“Event of Default” means with respect to any series of debt securities, any of the following:

No Event of Default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an Event of Default with respect to any other series of debt securities. The occurrence of certain Events of Default or an acceleration under the indenture may constitute an event of default under certain indebtedness of ours or our subsidiaries outstanding from time to time.

We will provide the trustee written notice of any Default or Event of Default within 30 days of becoming aware of the occurrence of such Default or Event of Default, which notice will describe in reasonable detail the status of such Default or Event of Default and what action we are taking or propose to take in respect thereof.

If an Event of Default with respect to debt securities of any series at the time outstanding occurs and is continuing, then the trustee or the holders of not less than 25% in principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the trustee if given by the holders), declare to be due and payable immediately the principal of

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(or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) and accrued and unpaid interest, if any, on all debt securities of that series. In the case of an Event of Default resulting from certain events of bankruptcy, insolvency or reorganization, the principal (or such specified amount) of and accrued and unpaid interest, if any, on all outstanding debt securities will become and be immediately due and payable without any declaration or other act on the part of the trustee or any holder of outstanding debt securities. At any time after a declaration of acceleration with respect to debt securities of any series has been made, but before a judgment or decree for payment of the money due has been obtained by the trustee, the holders of a majority in principal amount of the outstanding debt securities of that series may rescind and annul the acceleration if all Events of Default, other than the non-payment of accelerated principal and interest, if any, with respect to debt securities of that series, have been cured or waived as provided in the indenture. We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of such discount securities upon the occurrence of an Event of Default.

The indenture provides that the trustee may refuse to perform any duty or exercise any of its rights or powers under the indenture unless the trustee receives indemnity satisfactory to it against any cost, liability or expense which might be incurred by it in performing such duty or exercising such right or power. Subject to certain rights of the trustee, the holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee or exercising any trust or power conferred on the trustee with respect to the debt securities of that series.

No holder of any debt security of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the indenture or for the appointment of a receiver or trustee, or for any remedy under the indenture, unless:

Notwithstanding any other provision in the indenture, the holder of any debt security will have an absolute and unconditional right to receive payment of the principal of, premium and any interest on that debt security on or after the due dates expressed in that debt security and to institute suit for the enforcement of payment.

The indenture requires us, within 120 days after the end of our fiscal year, to furnish to the trustee a statement as to compliance with the indenture. If a Default or Event of Default occurs and is continuing with respect to the securities of any series and if it is known to a responsible officer of the trustee, the trustee shall send to each securityholder of the securities of that series notice of a Default or Event of Default within 90 days after it occurs or, if later, after a responsible officer of the trustee has knowledge of such Default or Event of Default. The indenture provides that the trustee may withhold notice to the holders of debt securities of any series of any Default or Event of Default (except in payment on any debt securities of that series) with respect to debt securities of that series if the trustee determines in good faith that withholding notice is in the interest of the holders of those debt securities.

Modification and Waiver

We and the trustee may modify, amend or supplement the indenture or the debt securities of any series without the consent of any holder of any debt security:

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We may also modify and amend the indenture with the consent of the holders of at least a majority in principal amount of the outstanding debt securities of each series affected by the modifications or amendments. We may not make any modification or amendment without the consent of the holders of each affected debt security then outstanding if that amendment will:

Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all debt securities of that series waive our compliance with provisions of the indenture. The holders of a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all the debt securities of such series waive any past default under the indenture with respect to that series and its consequences, except a default in the payment of the principal of, premium or any interest on any debt security of that series; provided, however, that the holders of a majority in principal amount of the outstanding debt securities of any series may rescind an acceleration and its consequences, including any related payment default that resulted from the acceleration.

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

Legal Defeasance

The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, we may be discharged from any and all obligations in respect of the debt securities of any series (subject to certain exceptions). We will be fixedso discharged upon the irrevocable deposit with the trustee, in trust, of money and/or U.S. government obligations or, in the

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case of debt securities denominated in a single currency other than U.S. dollars, government obligations of the government that issued or caused to be issued such currency, that, through the payment of interest and principal in accordance with their terms, will provide money or U.S. government obligations in an amount sufficient in the opinion of a nationally recognized firm of independent public accountants or investment bank to pay and discharge each installment of principal, premium and interest on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of those payments in accordance with the terms of the indenture and those debt securities.

This discharge may occur only if, among other things, we have delivered to the trustee an opinion of counsel stating that we have received from, or there has been published by, the certificateUnited States Internal Revenue Service a ruling or, since the date of designation relating to that series. The prospectus supplement also will containexecution of the indenture, there has been a description of certainchange in the applicable United States federal income tax consequenceslaw, in either case to the effect that, and based thereon such opinion shall confirm that, the holders of the debt securities of that series will not recognize income, gain or loss for United States federal income tax purposes as a result of the deposit, defeasance and discharge and will be subject to United States federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit, defeasance and discharge had not occurred.

Defeasance of Certain Covenants

The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, upon compliance with certain conditions:

We refer to this as covenant defeasance. The conditions include:

No Personal Liability of Directors, Officers, Employees or Stockholders

None of our past, present or future directors, officers, employees or stockholders, as such, will have any liability for any of our obligations under the debt securities or the indenture or for any claim based on, or in respect or by reason of, such obligations or their creation. By accepting a debt security, each holder waives and releases all such liability. This waiver and release is part of the consideration for the issue of the debt securities. However, this waiver and release may not be effective to waive liabilities under U.S. federal securities laws, and it is the view of the SEC that such a waiver is against public policy.

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Governing Law

The indenture and the debt securities, including any claim or controversy arising out of or relating to the purchase and ownership ofindenture or the series of preferred stock that is described in the prospectus supplement.

        Under the terms of our amended and restated certificate of incorporation, our board of directors is authorized to issue shares of preferred stock in one or more series without stockholder approval. Our board of directors has the discretion to determine the rights, preferences, privileges and restrictions, including voting rights, dividend rights, conversion rights, redemption privileges and liquidation preferences, of each series of preferred stock. There are no restrictions presently on the repurchase or redemption of any shares of our preferred stock.

        The prospectus supplement for a series of preferred stock will specify:

•

the maximum number of shares;



•

the designation of the shares;



•

the annual dividend rate, if any, whether the dividend rate is fixed or variable, the date or dates on which dividends will accrue, the dividend payment dates, and whether dividendssecurities, will be cumulative;



•

governed by the price and the terms and conditions for redemption, if any, including redemption at our option or at the option of the holders, including the time period for redemption, and any accumulated dividends or premiums;



•

the liquidation preference, if any, and any accumulated dividends upon the liquidation, dissolution or winding up of our affairs;



•

any sinking fund or similar provision, and, if so, the terms and provisions relating to the purpose and operation of the fund;



•

the terms and conditions, if any, for conversion or exchange of shares of any other class or classes of our capital stock or any series of any other class or classes, or of any other series of the same class, or any other securities or assets, including the price or the rate of conversion or exchange and the method, if any, of adjustment;



•

the voting rights; and



•

any or all other preferences and relative, participating, optional or other special rights, privileges or qualifications, limitations or restrictions.

        The issuance of additional shares of preferred stock will affect, and may adversely affect, the rights of holders of common stock. It is not possible to state the actual effect of the issuance of any additional shares of preferred stock on the rights of holders of common stock until our board of directors determines the specific rights attached to that preferred stock. The effects of issuing additional preferred stock could include one or more of the following:

•

restricting dividends on the common stock;



•

diluting the voting power of the common stock;



•

impairing the liquidation rights of the common stock; or



•

delaying or preventing changes in control or management of our company.

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fraction of the liquidation preference accorded each share of the applicable series of preferred stock, as set forth in the applicable prospectus supplement.

RedemptionWithdrawal of Stock

        If a seriesUnless the related depositary shares have been previously called for redemption, upon surrender of preferred stock underlying the depositary shares is subject to redemption,receipts at the office of the depositary, the holder of the depositary shares will be redeemed fromentitled to delivery, at the proceeds received byoffice of the depositary resulting fromto or upon his or her order, of the redemption, innumber of whole or in part,shares of the preferred stock heldand any money or other property represented by the depositary. depositary shares. If the depositary receipts delivered by the holder evidence a number of depositary shares in excess of the number of depositary shares representing the number of whole shares of preferred stock to be withdrawn, the depositary will deliver to the holder at the same time a new depositary receipt evidencing the excess number of depositary shares. In no event will the depositary deliver fractional shares of preferred stock upon surrender of depositary receipts. Holders of preferred stock thus withdrawn may not thereafter deposit those shares under the deposit agreement or receive depositary receipts evidencing depositary shares therefor.

Redemption of Depositary Shares

Whenever we redeem anyshares of preferred stock held by the depositary, the depositary will redeem as of the same redemption date the number of depositary shares representing shares of the preferred stock so redeemed. The depositary will mail

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the holders of a majority of the outstanding depositary shares. The deposit agreement may be terminated by the depositary or us only if:

•

●

all outstanding depositary shares have been redeemed; or

●

there has been a final distribution of the preferred stock in connection with our dissolution and such distribution has been made to all the holders of depositary shares.

Resignation and Removal of Depositary

The depositary shares have been redeemed;may resign at any time by delivering to us notice of its election to do so, and we may remove the depositary at any time. Any resignation or



•

there has been a final distribution of the preferred stock in connection with our dissolution and such distribution has been made to all the holders of depositary shares.

Charges of depositary

        We will pay all transfer and other taxes and governmental charges arising solely from the existence removal of the depositary arrangement. We will also pay chargestake effect upon our appointment of a successor depositary and its acceptance of such appointment. The successor depositary must be appointed within 60 days after delivery of the depositary in connection with:

•

the initial depositnotice of the preferred stock;



•

the initial issuance of the depositary shares;



•

any redemption of the preferred stock;resignation or removal and



•

all withdrawals of preferred stock by owners of depositary shares.

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Description of the terms described below, then the terms described below will be deemedSubscription Rights

We may issue subscription rights to have been superseded by that prospectus supplement.

purchase our Generalcommon stock

        Debt securities. These subscription rights may be issuedoffered independently or together with any other security offered hereby and may or may not be transferable by the stockholder receiving the subscription rights in separate series without limitation as to aggregate principal amount. We may specify a maximum aggregate principal amount for the debt securitiessuch offering. In connection with any offering of any series.

        We are not limited as to the amount of debt securitiessubscription rights, we may issue underenter into a standby arrangement with one or more underwriters or other purchasers pursuant to which the indentures. Unless otherwise provided in a prospectus supplement, a series of debt securitiesunderwriters or other purchasers may be reopenedrequired to issue additional debtpurchase any securities ofremaining unsubscribed for after such series.offering.

The prospectus supplement relating to a particular series of debt securities will set forth:

•

whether the debt securities are senior or subordinated;



•

the offering price;



•

the title;



•

any limit on the aggregate principal amount;



•

the person who shall be entitled to receive interest, if other than the record holder on the record date;



•

the date or dates the principal will be payable;



•

the interest rate or rates, which may be fixed or variable,subscription rights we offer, if any, the date from which interest will, accrue, the interest payment dates and the regular record dates, or the method for calculating the dates and rates;



•

the place where payments may be made;

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agreements in their entirety and may not contain all the information that you may find useful. We urge you to read the applicable subscription right agreements because they, and not the summaries, define your rights as holders of the units.subscription rights. For more information, please review the forms of the relevant subscription right agreements, which will be filed with the SEC promptly after the offering of unitssubscription rights and will be available as described underin the heading "Wheresection of this prospectus captioned “Where You Can Find More Information."

”

Table of Contents

PLAN OF DISTRIBUTION
Description of Purchase Contracts

        WeThe following description summarizes the general features of the purchase contracts that we may selloffer under this prospectus. Although the securities offered throughfeatures we have summarized below will generally apply to any future purchase contracts we may offer under this prospectus, (1) to or through underwriters or dealers, (2) directly to purchasers, including our affiliates, (3) through agents, or (4) through a combinationwe will describe the particular terms of any these methods.purchase contracts that we may offer in more detail in the applicable prospectus supplement. The securitiesspecific terms of any purchase contracts may be distributed atdiffer from the description provided below as a fixed price or prices,result of negotiations with third parties in connection with the issuance of those purchase contracts, as well as for other reasons. Because the terms of any purchase contracts we offer under a prospectus supplement may differ from the terms we describe below, you should rely solely on information in the applicable prospectus supplement if that summary is different from the summary in this prospectus.

We will incorporate by reference into the registration statement of which this prospectus is a part the form of any purchase contract that we may be changed, market prices prevailing atoffer under this prospectus before the timesale of sale, pricesthe related purchase contract. We urge you to read any applicable prospectus supplement related to specific purchase contracts being offered, as well as the prevailing market prices, or negotiated prices. The prospectus supplement will include the following information:

•

complete instruments that contain the terms of the offering;



•

securities that are subject to those purchase contracts. Certain of those instruments, or forms of those instruments, have been filed as exhibits to the namesregistration statement of any underwriterswhich this prospectus is a part, and supplements to those instruments or agents;



•

forms may be incorporated by reference into the nameregistration statement of which this prospectus is a part from reports we file with the SEC.

We may issue purchase contracts, including contracts obligating holders to purchase from us, and for us to sell to holders, a specific or namesvariable number of any managing underwriterour securities at a future date or underwriters;



•

dates. Alternatively, the purchase contracts may obligate us to purchase from holders, and obligate holders to sell to us, a specific or varying number of our securities.

If we offer any purchase contracts, certain terms of that series of purchase contracts will be described in the applicable prospectus supplement, including, without limitation, the following:

●

the price of the securities or other property subject to the purchase contracts (which may be determined by reference to a specific formula described in the purchase contracts);

●

whether the purchase contracts are issued separately, or as a part of units each consisting of a purchase contract and one or more of our other securities, including U.S. Treasury securities, securing the holder’s obligations under the purchase contract;

●

any requirement for us to make periodic payments to holders or vice versa, and whether the payments are unsecured or pre-funded;

●

any provisions relating to any security provided for the purchase contracts;

●

whether the purchase contracts obligate the holder or us to purchase or sell, or both purchase and sell, the securities subject to purchase under the purchase contract, and the nature and amount of each of those securities, or the method of determining those amounts;

●

whether the purchase contracts are to be prepaid or not;

●

whether the purchase contracts are to be settled by delivery, or by reference or linkage to the value, performance or level of the securities subject to purchase under the purchase contract;

●

any acceleration, cancellation, termination or other provisions relating to the settlement of the purchase contracts;

●

a discussion of certain U.S. federal income tax considerations applicable to the purchase contracts;

●

whether the purchase contracts will be issued in fully registered or global form; and

●

any other terms of the purchase contracts and any securities subject to such purchase contracts.

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Description of Units

We may issue units comprising two or more securities described in this prospectus in any combination. For example, we might issue units consisting of a combination of debt securities and warrants to purchase common stock. The following description sets forth certain general terms and provisions of the securities;

Sale through underwritersthat we must pay. Any such agent will be acting on a best efforts basis for the period of its appointment or, dealers

        If underwriters areif indicated in the applicable prospectus supplement, on a firm commitment basis. This prospectus may be used in connection with any offering of our securities through any of these methods or other methods described in the sale, the underwriters will acquireapplicable prospectus supplement.

The distribution of the securities for their own account, including through underwriting, purchase, security lending or repurchase agreements with us. The underwriters may resell the securitiesbe effected from time to time in one or more transactions,transactions:

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Each prospectus supplement will describe the method of distribution of the securities and any applicable restrictions.

The prospectus supplement with respect to the securities of a particular series will describe the terms of the offering of the securities, including negotiated transactions. Underwriters may sellthe following:

If any underwriters or agents are utilized in the sale of the securities in order to facilitate transactions in anyrespect of our other securities (described inwhich this prospectus is delivered, we will enter into an underwriting agreement or otherwise), including other public or private transactionsagreement with them at the time of sale to them, and short sales. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Unless otherwise indicatedwe will set forth in the prospectus supplement the obligations of the underwritersrelating to purchase the securities will be subject to certain conditions, and the underwriters will be obligated to purchase all the offered securities if they purchase any of them. The underwriters may change from time to time any initial publicsuch offering price and any discounts or concessions allowed or reallowed or paid to dealers. The prospectus supplement will include the names of the principal underwriters or agents and the respective amount of securities underwritten, the natureterms of the obligation of the underwriters to take the securities and the nature of any material relationship between an underwriter and us.related agreement with them.

If dealers are useda dealer is utilized in the sale of the securities offered through thisin respect of which the prospectus is delivered, we will sell thesuch securities to themthe dealer, as principals. Theyprincipal. The dealer may then resell thosesuch securities to the public at varying prices to be determined by the dealerssuch dealer at the time of resale. The prospectus supplement will include the names of the dealers and the terms of the transaction.

Direct sales and sales through agents

        We may sell the securities offered through this prospectus directly. In this case, no underwriters or agents would be involved. Such securities may also be sold through agents designated from time to time. The prospectus supplement will name any agent involved in theIf we offer or sale of the offered securities and will describe any commissions payable to the agent by us. Unless otherwise indicated in

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In order to facilitate the offering of the securities, any underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the securities or any other securities the prices of which may be used to determine payments on such securities. Specifically, any underwriters may over-allot in connection with the offering, creating a short position for their own accounts. In addition, to cover over-allotments or to stabilize the price of the securities or of any such other securities, the underwriters may bid for, and purchase, the securities or any such other securities in the open market. Finally, in any offering of the securities through a syndicate of underwriters, the underwriting syndicate may reclaim selling concessions allowed to an underwriter or a dealer for distributing the securities in the offering if the syndicate repurchases previously distributed securities in transactions to cover syndicate short positions, in stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the securities above independent market levels. Any such underwriters are not required to engage in these activities and may end any of these activities at any time.

Under Rule 15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in two business days, unless the parties to any such trade expressly agree otherwise. The applicable prospectus supplement may provide that the original issue date for your securities may be more than two scheduled business days after the trade date for your securities. Accordingly, in such a case, if you wish to trade securities on any date prior to the third business day before the original issue date for your securities, you will be required, by virtue of the fact that your securities initially are expected to settle in more than three scheduled business days after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

The securities may be new issues of securities and may have no established trading market. The securities may or may not be listed on a national securities exchange. We can make no assurance as to the liquidity of or the existence of trading markets for any of the securities.

LEGAL MATTERS
Legal Matters

The validity of the securities offered by this prospectushereby will be passed upon for us by Wilson Sonsini Goodrich & Rosati, Professional Corporation, Palo Alto, California. Additional legal matters may be passed on for us, or any underwriters, dealers or agents by counsel we will name in the applicable prospectus supplement.

EXPERTS
Experts

The consolidated financial statements and the effectiveness of internal control over financial reporting of AXT, Inc. as of December 31, 2020 and subsidiaries2019 and for each of the three years in the period ended December 31, 2020 incorporated in this registration statement on Form S-3 by reference to the Annual Report on Form 10-K for the year ended December 31, 20102020, have been so incorporated by reference herein in reliance uponon the report of Burr Pilger Mayer, Inc.,BPM, an independent registered public accounting firm, and upongiven on the authority of said firm as experts in accountingauditing and auditing.accounting.

WHERE YOU CAN FIND MORE INFORMATION
Where You Can Find More Information

We file annual, quarterly and othercurrent reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC'sSEC’s website at http://www.sec.gov. You may also read and copy any document we file at the SEC's Public Reference Room at 100 F Street, NE, Washington, D.C. 20549. Please callwww.sec.gov. Copies of certain information filed by us with the SEC are also available on our website at 1-800-SEC-0330 for further informationwww.axt.com. Information accessible on the Public Reference Room. Our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q,or through our website is not a part of this prospectus.

This prospectus and Current Reports on Form 8-K, including any amendments to those reports, and other informationprospectus supplement is part of a registration statement that we file with or furnish to the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act can also be accessed free of charge through the Internet. These filings will be available as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC.

        We have filed with the SEC a registration statement under the Securities Act of 1933 relating to the offering of these securities. The registration statement, including the attached exhibits, contains additional relevant information about us and the securities. This prospectus doesdo not contain all of the information set forth in the registration statement. You can obtain a copy ofshould review the information and exhibits in the registration statement at prescribed rates, fromfor further information on us and our consolidated subsidiaries and the SEC atsecurities that we are offering. Forms of any indenture or other documents establishing the address listed above. Theterms of the offered securities are filed as exhibits to the registration statement of which this prospectus forms a part or under cover of a Current Report on Form 8-K and theincorporated in this prospectus by reference. Statements in this prospectus or any prospectus supplement about these documents referred to below under "Incorporation by Reference" are also available on our Internet website, www.axt.com. We have not incorporatedsummaries and each statement is qualified in all respects by reference into this prospectusto the information on our website, and youdocument to which it refers. You should not consider it to beread the actual documents for a partmore complete description of this prospectus.

the relevant matters.

Table of Contents

INFORMATION INCORPORATED BY REFERENCE
Incorporation by Reference

The SEC allows us to incorporate by reference into this prospectus certainmuch of the information that we file with it,the SEC, which means that we can disclose important information to you by referring you to those publicly available documents. The information incorporatedthat we incorporate by reference in this prospectus is considered to be a part of this prospectus, and information thatprospectus. Because we file laterare incorporating by reference future filings with the SEC, will automatically updatethis prospectus is continually updated and those future filings may modify or supersede some of the information containedincluded or incorporated by reference in this prospectus. This means that you must look at all of the SEC filings that we incorporate by reference to determine if any of the statements in this prospectus andor in any accompanyingdocument previously incorporated by reference have been modified or superseded. This prospectus supplement. We incorporateincorporates by reference the

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documents listed below thatand any future filings we have previously filed with the SEC (excluding any portions of any Form 8-K that are not deemed "filed" pursuant to the General Instructions of Form 8-K):

•

Annual Report on Form 10-K for the fiscal year ended December 31, 2010, including the information specifically incorporated by reference into the Form 10-K from our definitive proxy statement for the 2011 Annual Meeting of Stockholders;



•

Quarterly Reports on Form 10-Q for the fiscal quarters ended March 31, 2011 and June 30, 2011;



•

Current Reports on Form 8-K filed January 3, 2011, May 23, 2011; and



•

The description of our common stock contained in the Registration Statement on Form 8-A relating thereto, including any amendment or report filed for the purpose of updating such description.

        We also incorporate by reference into this prospectus additional documents that we may filemake with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act prior(in each case, other than those documents or the portions of those documents furnished pursuant to Items 2.02 or 7.01 of any Current Report on Form 8-K and, except as may be noted in any such Form 8-K, exhibits filed on such form that are related to such information), until the completion or terminationoffering of the offering, including all such documents we may file with the SEC after the date of the initial registration statement and prior to the effectiveness of the registration statement, but excluding any information deemed furnished and not filed with the SEC. Any statements contained in a previously filed document incorporated by reference into this prospectus is deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus, or in a subsequently filed document also incorporated by reference herein, modifies or supersedes that statement.

        This prospectus may contain information that updates, modifies or is contrary to information in one or more of the documents incorporated by reference in this prospectus. You should rely only on the information incorporated by reference or provided in this prospectus. We have not authorized anyone else to provide you with different information. You should not assume that the information in this prospectus is accurate as of any date other than the date of this prospectus or the date of the documents incorporated by reference in this prospectus.

        We will provide to each person, including any beneficial owner, to whom this prospectus is delivered, upon written or oral request, at no cost to the requester, a copy of any and all of the information that is incorporated by reference in this prospectus.

        Requests for such documents should be directed to:

AXT, Inc.
4281 Technology Drive
Fremont, California 94538
Attn: Investor Relations

        You may also access the documents incorporated by reference in this prospectus through our website at www.axt.com. Except for the specific incorporated documents listed above, no information available on or through our website shall be deemed to be incorporated in this prospectus orsecurities under the registration statement of which itthis prospectus forms a part.part is terminated or completed:

TableYou may request a copy of Contentsthese filings, at no cost, by writing or telephoning us at the following address:

$60,000,000

AXT, Inc.

Common Stock
Preferred Stock
Depositary Shares
Warrants
Debt Securities
Units4281 Technology Drive

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PART II

Table of Contents

PART II

INFORMATION NOT REQUIRED IN THE PROSPECTUS

Item 14.    Other Expenses of Issuance and Distribution

The following table sets forth the costs andestimated expenses other than underwriting discounts and commissions, payable by the registrant in connection with the saleissuance and distribution of the securities being registeredregistered: