AXCELIS TECHNOLOGIES INC 10-Q

Item 1. Financial Statements. ​ Axcelis Technologies, Inc. Consolidated Statements of Operations (In thousands, except per share amounts) (Unaudited) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ ​ ​ September 30, ​ September 30, ​ ​ 2023 2022 2023 2022 Revenue: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Product ​ $ 283,367 ​ $ 221,540 ​ $ 795,047 ​ $ 631,998 ​ Services ​ 8,959 ​ 7,635 ​ 25,269 ​ 21,949 ​ Total revenue ​ 292,326 ​ 229,175 ​ 820,316 ​ 653,947 ​ Cost of revenue: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Product ​ 154,798 ​ 118,992 ​ 444,311 ​ 342,387 ​ Services ​ 7,844 ​ 6,862 ​ 22,600 ​ 19,291 ​ Total cost of revenue ​ 162,642 ​ 125,854 ​ 466,911 ​ 361,678 ​ Gross profit ​ 129,684 ​ 103,321 ​ 353,405 ​ 292,269 ​ Operating expenses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Research and development ​ 24,093 ​ 20,563 ​ 71,996 ​ 56,267 ​ Sales and marketing ​ 16,465 ​ 14,573 ​ 46,146 ​ 38,567 ​ General and administrative ​ 17,446 ​ 14,983 ​ 48,519 ​ 41,163 ​ Total operating expenses ​ 58,004 ​ 50,119 ​ 166,661 ​ 135,997 ​ Income from operations ​ 71,680 ​ 53,202 ​ 186,744 ​ 156,272 ​ Other income (expense): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest income ​ 4,580 ​ 1,111 ​ 12,824 ​ 1,558 ​ Interest expense ​ ( 1,325 ) ​ ( 1,333 ) ​ ( 4,027 ) ​ ( 4,101 ) ​ Other, net ​ ( 1,260 ) ​ ( 7,971 ) ​ ( 4,348 ) ​ ( 14,640 ) ​ Total other income (expense) ​ 1,995 ​ ( 8,193 ) ​ 4,449 ​ ( 17,183 ) ​ Income before income taxes ​ 73,675 ​ 45,009 ​ 191,193 ​ 139,089 ​ Income tax provision ​ 7,744 ​ 4,726 ​ 15,986 ​ 13,002 ​ Net income ​ $ 65,931 ​ $ 40,283 ​ $ 175,207 ​ $ 126,087 ​ Net income per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ $ 2.01 ​ $ 1.22 ​ $ 5.35 ​ $ 3.81 ​ Diluted ​ $ 1.99 ​ $ 1.21 ​ $ 5.28 ​ $ 3.75 ​ Shares used in computing net income per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic weighted average shares of common stock ​ 32,807 ​ 33,011 ​ 32,775 ​ 33,116 ​ Diluted weighted average shares of common stock ​ 33,159 ​ 33,389 ​ 33,208 ​ 33,638 ​ ​ See accompanying Notes to these Consolidated Financial Statements (Unaudited) ​ ​ 3 Table of Contents ​ Axcelis Technologies, Inc. Consolidated Statements of Comprehensive Income (In thousands) (Unaudited) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2023 2022 2023 2022 Net income ​ $ 65,931 ​ $ 40,283 ​ $ 175,207 ​ $ 126,087 ​ Other comprehensive loss: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign currency translation adjustments ​ ( 1,231 ) ​ ( 3,690 ) ​ ( 2,192 ) ​ ( 7,561 ) ​ Amortization of actuarial net gain and other adjustments from pension plan, net of tax ​ — ​ 8 ​ — ​ 25 ​ Total other comprehensive loss ​ ​ ( 1,231 ) ​ ​ ( 3,682 ) ​ ​ ( 2,192 ) ​ ​ ( 7,536 ) ​ Comprehensive income ​ $ 64,700 ​ $ 36,601 ​ $ 173,015 ​ $ 118,551 ​ ​ See accompanying Notes to these Consolidated Financial Statements (Unaudited) ​ ​ 4 Table of Contents ​ Axcelis Technologies, Inc. Consolidated Balance Sheets (In thousands, except per share amounts) (Unaudited) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2023 ​ 2022 ASSETS ​ Current assets: ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 142,300 ​ $ 185,595 ​ Short-term investments ​ 318,710 ​ 246,571 ​ Accounts receivable, net ​ 192,327 ​ 169,773 ​ Inventories, net ​ 312,223 ​ 242,406 ​ Prepaid expenses and other current assets ​ 49,481 ​ 33,300 ​ Total current assets ​ 1,015,041 ​ 877,645 ​ Property, plant and equipment, net ​ 47,169 ​ 39,664 ​ Operating lease assets ​ ​ 31,082 ​ ​ 12,146 ​ Finance lease assets, net ​ ​ 16,981 ​ ​ 17,942 ​ Long-term restricted cash ​ 6,650 ​ 752 ​ Deferred income taxes ​ ​ 44,323 ​ ​ 31,701 ​ Other assets ​ 40,448 ​ 33,791 ​ Total assets ​ $ 1,201,694 ​ $ 1,013,641 ​ LIABILITIES AND STOCKHOLDERS’ EQUITY ​ Current liabilities: ​ ​ ​ ​ ​ ​ ​ Accounts payable ​ $ 60,061 ​ $ 62,346 ​ Accrued compensation ​ 26,535 ​ 35,540 ​ Warranty ​ 11,464 ​ 8,299 ​ Income taxes ​ 582 ​ 4,304 ​ Deferred revenue ​ 148,299 ​ 123,471 ​ Current portion of finance lease obligation ​ 1,438 ​ 1,229 ​ Other current liabilities ​ 12,799 ​ 12,943 ​ Total current liabilities ​ 261,178 ​ 248,132 ​ Long-term finance lease obligation ​ 44,070 ​ 45,185 ​ Long-term deferred revenue ​ 53,730 ​ 31,306 ​ Other long-term liabilities ​ 41,745 ​ 21,762 ​ Total liabilities ​ 400,723 ​ 346,385 ​ Commitments and contingencies (Note 16) ​ ​ ​ ​ ​ ​ ​ Stockholders’ equity: ​ ​ ​ ​ ​ ​ ​ Common stock, $ 0.001 par value, 75,000 shares authorized; 32,772 shares issued and outstanding at September 30, 2023; 32,775 shares issued and outstanding at December 31, 2022 ​ 33 ​ 33 ​ Additional paid-in capital ​ 543,577 ​ 550,299 ​ Retained earnings ​ 261,521 ​ 118,892 ​ Accumulated other comprehensive loss ​ ( 4,160 ) ​ ( 1,968 ) ​ Total stockholders’ equity ​ 800,971 ​ 667,256 ​ Total liabilities and stockholders’ equity ​ $ 1,201,694 ​ $ 1,013,641 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ See accompanying Notes to these Consolidated Financial Statements (Unaudited) ​ 5 Table of Contents Axcelis Technologies, Inc. Consolidated Statements of Stockholders’ Equity (In thousands) (Unaudited) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Accumulated ​ Accumulated ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Additional ​ Deficit) ​ Other ​ Total ​ ​ ​ Common Stock ​ Paid-in ​ Retained ​ Comprehensive ​ Stockholders’ ​ ​ Shares Amount Capital Earnings Income Equity Balance at December 31, 2021 ​ ​ 33,240 ​ $ 33 ​ $ 559,883 ​ $ ( 22,722 ) ​ $ 1,765 ​ $ 538,959 ​ Net income ​ — ​ — ​ — ​ 41,614 ​ — ​ 41,614 ​ Foreign currency translation adjustments ​ — ​ — ​ — ​ — ​ ( 1,186 ) ​ ( 1,186 ) ​ Change in pension obligation ​ — ​ — ​ — ​ — ​ 9 ​ 9 ​ Exercise of stock options ​ 41 ​ — ​ 491 ​ — ​ — ​ 491 ​ Issuance of common stock on restricted stock units, net of shares withheld ​ 67 ​ — ​ ( 3,315 ) ​ — ​ — ​ ( 3,315 ) ​ Stock-based compensation expense ​ ​ — ​ ​ — ​ 2,701 ​ — ​ — ​ 2,701 ​ Repurchase of common stock ​ ( 284 ) ​ — ​ ( 5,127 ) ​ ( 14,873 ) ​ — ​ ( 20,000 ) ​ Balance at March 31, 2022 ​ 33,064 ​ $ 33 ​ $ 554,633 ​ $ 4,019 ​ $ 588 ​ $ 559,273 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income ​ — ​ — ​ — ​ 44,189 ​ — ​ 44,189 ​ Foreign currency translation adjustments ​ — ​ — ​ — ​ — ​ ( 2,685 ) ​ ( 2,685 ) ​ Change in pension obligation ​ — ​ — ​ — ​ — ​ 8 ​ 8 ​ Exercise of stock options ​ 25 ​ — ​ 298 ​ — ​ — ​ 298 ​ Issuance of stock under Employee Stock Purchase Plan ​ 15 ​ — ​ 711 ​ — ​ — ​ 711 ​ Issuance of common stock on restricted stock units, net of shares withheld ​ 205 ​ — ​ ( 5,896 ) ​ — ​ — ​ ( 5,896 ) ​ Stock-based compensation expense ​ ​ — ​ ​ — ​ ​ 3,527 ​ ​ — ​ ​ — ​ ​ 3,527 ​ Repurchase of common stock ​ ​ ( 215 ) ​ — ​ ( 3,872 ) ​ ( 8,626 ) ​ — ​ ( 12,498 ) ​ Balance at June 30, 2022 ​ 33,094 ​ $ 33 ​ $ 549,401 ​ $ 39,582 ​ $ ( 2,089 ) ​ $ 586,927 ​ Net income ​ — ​ — ​ — ​ 40,283 ​ — ​ 40,283 ​ Foreign currency translation adjustments ​ — ​ — ​ — ​ — ​ ( 3,690 ) ​ ( 3,690 ) ​ Change in pension obligation ​ — ​ — ​ — ​ — ​ 8 ​ 8 ​ Exercise of stock options ​ 30 ​ — ​ 367 ​ — ​ — ​ 367 ​ Issuance of common stock on restricted stock units, net of stock withheld ​ 8 ​ — ​ ( 70 ) ​ — ​ — ​ ( 70 ) ​ Stock-based compensation expense ​ ​ — ​ ​ — ​ ​ 3,562 ​ ​ — ​ ​ — ​ ​ 3,562 ​ Repurchase of common stock ​ ( 195 ) ​ — ​ ( 3,525 ) ​ ( 8,972 ) ​ — ​ ( 12,497 ) ​ Balance at September 30, 2022 ​ 32,937 ​ $ 33 ​ $ 549,735 ​ $ 70,893 ​ $ ( 5,771 ) ​ $ 614,890 ​ ​ ​ ​ See accompanying Notes to these Consolidated Financial Statements (Unaudited) ​ 6 Table of Contents Axcelis Technologies, Inc. Consolidated Statements of Stockholders’ Equity (In thousands) (Unaudited) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Additional ​ ​ ​ Other ​ Total ​ ​ ​ Common Stock ​ Paid-in ​ Retained ​ Comprehensive ​ Stockholders’ ​ ​ Shares Amount Capital Earnings Loss Equity Balance at December 31, 2022 ​ ​ 32,775 ​ $ 33 ​ $ 550,299 ​ $ 118,892 ​ $ ( 1,968 ) ​ $ 667,256 Net income ​ — ​ — ​ — ​ 47,697 ​ — ​ 47,697 Foreign currency translation adjustments ​ — ​ — ​ — ​ — ​ 50 ​ 50 Exercise of stock options ​ 2 ​ — ​ 25 ​ — ​ ​ ​ 25 Issuance of common stock on restricted stock units, net of shares withheld ​ 56 ​ — ​ ( 3,907 ) ​ — ​ — ​ ( 3,907 ) Stock-based compensation expense ​ ​ — ​ — ​ 3,199 ​ — ​ — ​ 3,199 Repurchase of common stock ​ ( 107 ) ​ — ​ ( 1,924 ) ​ ( 10,575 ) ​ — ​ ( 12,499 ) Balance at March 31, 2023 ​ 32,726 ​ $ 33 ​ $ 547,692 ​ $ 156,014 ​ $ ( 1,918 ) ​ $ 701,821 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income ​ — ​ — ​ — ​ 61,579 ​ — ​ 61,579 Foreign currency translation adjustments ​ — ​ — ​ — ​ — ​ ( 1,011 ) ​ ( 1,011 ) Issuance of stock under Employee Stock Purchase Plan ​ 6 ​ — ​ 957 ​ — ​ — ​ 957 Issuance of common stock on restricted stock units, net of shares withheld ​ 199 ​ — ​ ( 11,558 ) ​ — ​ — ​ ( 11,558 ) Stock-based compensation expense ​ — ​ — ​ 4,749 ​ ​ ​ — ​ 4,749 Repurchase of common stock ​ ​ ( 95 ) ​ ​ — ​ ​ ( 1,720 ) ​ ​ ( 10,780 ) ​ ​ — ​ ​ ( 12,500 ) Balance at June 30, 2023 ​ 32,836 ​ $ 33 ​ $ 540,120 ​ $ 206,813 ​ $ ( 2,929 ) ​ $ 744,037 Net income ​ — ​ — ​ — ​ 65,931 ​ — ​ 65,931 Foreign currency translation adjustments ​ — ​ — ​ — ​ — ​ ( 1,231 ) ​ ( 1,231 ) Issuance of common stock on restricted stock units, net of stock withheld ​ 7 ​ — ​ ( 349 ) ​ — ​ — ​ ( 349 ) Stock-based compensation expense ​ ​ — ​ — ​ 5,082 ​ — ​ — ​ 5,082 Repurchase of common stock ​ ( 71 ) ​ — ​ ( 1,276 ) ​ ( 11,223 ) ​ — ​ ( 12,499 ) Balance at September 30, 2023 ​ 32,772 ​ $ 33 ​ $ 543,577 ​ $ 261,521 ​ $ ( 4,160 ) ​ $ 800,971 ​ ​ See accompanying Notes to these Consolidated Financial Statements (Unaudited) 7 Table of Contents Axcelis Technologies, Inc. Consolidated Statements of Cash Flows (In thousands) (Unaudited) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended ​ ​ ​ September 30, ​ ​ 2023 2022 Cash flows from operating activities ​ ​ ​ ​ ​ ​ ​ Net income ​ $ 175,207 ​ $ 126,087 ​ Adjustments to reconcile net income to net cash provided by operating activities: ​ ​ ​ ​ ​ ​ ​ Depreciation and amortization ​ 9,488 ​ 8,614 ​ Deferred income taxes ​ ( 12,623 ) ​ 6,416 ​ Stock-based compensation expense ​ 13,030 ​ 9,790 ​ Provision for doubtful accounts ​ ​ 749 ​ ​ — ​ Provision for excess and obsolete inventory ​ 3,912 ​ 3,292 ​ Accretion of discounts and premiums on marketable securities ​ ​ ( 8,463 ) ​ ​ — ​ Currency loss on foreign denominated transactions ​ ​ 7,487 ​ ​ — ​ Changes in operating assets and liabilities: ​ ​ ​ ​ ​ ​ ​ Accounts receivable ​ ( 26,674 ) ​ ( 77,449 ) ​ Inventories ​ ( 79,494 ) ​ ( 49,699 ) ​ Prepaid expenses and other current assets ​ ( 16,493 ) ​ ( 4,861 ) ​ Accounts payable and other current liabilities ​ ( 8,916 ) ​ 17,695 ​ Deferred revenue ​ 47,704 ​ 54,814 ​ Income taxes ​ ( 3,672 ) ​ ( 274 ) ​ Other assets and liabilities ​ ( 9,948 ) ​ ( 1,202 ) ​ Net cash provided by operating activities ​ 91,294 ​ 93,223 ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash flows from investing activities ​ ​ ​ ​ ​ ​ ​ Expenditures for property, plant and equipment and capitalized software ​ ( 10,503 ) ​ ( 6,876 ) ​ Purchase of short-term investments ​ ( 271,583 ) ​ ( 33,576 ) ​ Maturities of short-term investments ​ 207,907 ​ — ​ Net cash used in investing activities ​ ( 74,179 ) ​ ( 40,452 ) ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash flows from financing activities ​ ​ ​ ​ ​ ​ ​ Net settlement on restricted stock grants ​ ( 15,814 ) ​ ( 9,281 ) ​ Repurchase of common stock ​ ( 37,498 ) ​ ( 44,995 ) ​ Proceeds from Employee Stock Purchase Plan purchases ​ 957 ​ 711 ​ Principal payments on finance lease obligation ​ ​ ( 915 ) ​ ​ ( 728 ) ​ Proceeds from exercise of stock options ​ ​ 25 ​ ​ 1,156 ​ Net cash used in financing activities ​ ( 53,245 ) ​ ( 53,137 ) ​ ​ ​ ​ ​ ​ ​ ​ ​ Effect of exchange rate changes on cash and cash equivalents ​ ( 1,267 ) ​ 13,987 ​ Net (decrease) increase in cash, cash equivalents and restricted cash ​ ( 37,397 ) ​ 13,621 ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash, cash equivalents and restricted cash at beginning of period ​ 186,347 ​ 295,680 ​ Cash, cash equivalents and restricted cash at end of period ​ $ 148,950 ​ $ 309,301 ​ ​ See accompanying Notes to these Consolidated Financial Statements (Unaudited) ​ 8 Table of Contents Axcelis Technologies, Inc. Notes to Consolidated Financial Statements (Unaudited) ​ Note 1. Nature of Business ​ Axcelis Technologies, Inc. (“Axcelis” or the “Company”) was incorporated in Delaware in 1995 and is a producer of ion implantation equipment used in the fabrication of semiconductor chips in the United States, Europe and Asia. In addition, we provide extensive worldwide aftermarket service and support, including spare parts, equipment upgrades, used equipment and maintenance services to the semiconductor industry. ​ The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments which are of a normal recurring nature and considered necessary for a fair presentation of these financial statements have been included. Operating results for the interim periods presented are not necessarily indicative of the results that may be expected for other interim periods or for the year as a whole. ​ The balance sheet at December 31, 2022 has been derived from the audited consolidated financial statements at that date but does not include all the information and footnotes required by generally accepted accounting principles for complete financial statements. As of September 30, 2023, there have been no material changes in the Company’s significant accounting policies. For further information, refer to the consolidated financial statements and footnotes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. ​ ​ Note 2. Stock-Based Compensation ​ We maintain the Axcelis Technologies, Inc. 2012 Equity Incentive Plan, as amended (the “2012 Equity Plan”), an Internal Revenue Code Section 423 plan, which became effective on May 2, 2012, and permits the issuance of options, restricted stock, restricted stock units (“RSUs”) and performance awards to selected employees, directors and consultants of the Company. ​ The 2012 Equity Plan is more fully described in Note 13 to the consolidated financial statements in our Annual Report on Form 10-K for the year ended December 31, 2022. ​ We recognized stock-based compensation expense of $ 5.1 million and $ 3.6 million for the three-month periods ended September 30, 2023 and 2022, respectively. We recognized stock-based compensation expense of $ 13.0 million and $ 9.8 million for the nine-month periods ended September 30, 2023 and 2022, respectively. These amounts include compensation expense related to RSUs, non-qualified stock options and stock issued to participants under the 2020 Employee Stock Purchase Plan (the “2020 ESPP”). ​ In the three-month period ended September 30, 2023, we issued 7,320 shares of common stock upon vesting of RSUs. In the three-month period ended September 30, 2022, we issued 38,507 shares of common stock upon vesting of RSUs and stock option exercises. In the three-month period ended September 30, 2023, we received no proceeds in connection with the exercise of stock options. In the three-month period ended September 30, 2022, we received proceeds of $ 0.4 million in connection with the exercise of stock options. ​ In the nine-month periods ended September 30, 2023 and 2022, we issued 0.3 million and 0.4 million shares of common stock, respectively, upon stock option exercises, purchases under the 2020 ESPP and vesting of RSUs. In the nine-month periods ended September 30, 2023 and 2022, we received proceeds of $ 1.0 million and $ 1.9 million, respectively, in connection with the exercise of stock options and purchases under the 2020 ESPP. ​ Note 3. Leases ​ We have operating leases for manufacturing, office space, warehouse space, computer and office equipment and vehicles used in our business operations. We have a finance lease in relation to the 2015 sale-leaseback of our corporate headquarters in Beverly, Massachusetts. We review all agreements to determine if the agreement contains a lease 9 Table of Contents component. An agreement contains a lease component if it provides for the use of a specific physical space or a specific physical item. ​ We recognize operating lease obligations under Accounting Standards Codification Topic 842, Leases (“Topic 842”). The guidance in Topic 842 requires recognition of lease assets and related liabilities on a discounted basis using the explicit or implicit discount rate stated within the agreement. We recognize a corresponding right-of-use asset, which is initially determined based upon the net present value of the associated liability and is adjusted for deferred costs and possible impairment, if any. For those lease agreements that do not indicate the applicable discount rate, we use our incremental borrowing rate. We have made the following policy elections: (i) operating leases with an initial term of 12 months or less are not recorded on the consolidated balance sheet; (ii) we recognize lease expense for operating leases on a straight-line basis over the lease term; and (iii) we account for lease components and non-lease components that are fixed payments as one component. Some of our operating leases include one or more options to renew , with renewal terms that can extend the respective lease term by one to three years . The exercise of lease renewal options is at our sole discretion. For lease extensions that are reasonably certain to occur, we have included the renewal periods in our calculation of the net present value of the lease obligation and related right-of-use asset. Certain leases also include options to purchase the leased property. The depreciable life of certain assets and leasehold improvements is limited by the expected lease term, unless there is a transfer of title or purchase option reasonably certain of exercise. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants. The amounts of operating and finance lease right-of-use assets and related lease obligations recorded within our consolidated balance sheets are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ ​ Leases Classification ​ 2023 2022 ​ Assets ​ ​ (in thousands) ​ ​ Operating leases Operating lease assets ​ $ 31,082 ​ $ 12,146 ​ ​ ​ Finance lease Finance lease assets* ​ 16,981 ​ 17,942 ​ ​ ​ Total leased assets ​ ​ $ 48,063 ​ $ 30,088 ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Other current liabilities ​ $ 5,001 ​ $ 5,367 ​ ​ ​ Finance Current portion of finance lease obligation ​ ​ 1,438 ​ ​ 1,229 ​ ​ ​ Non-current ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Other long-term liabilities ​ ​ 25,850 ​ ​ 6,931 ​ ​ ​ Finance Finance lease obligation ​ 44,070 ​ 45,185 ​ ​ ​ Total lease liabilities ​ ​ $ 76,359 ​ $ 58,712 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ *Finance lease assets are recorded net of accumulated depreciation of $ 46.7 million and include $ 0.6 million of prepaid financing costs as of September 30, 2023. Finance lease assets are recorded net of accumulated depreciation of $ 45.9 million and include $ 0.6 million of prepaid financing costs as of December 31, 2022. ​ ​ ​ ​ ​ All of our operating lease office locations support selling and servicing functions. Our Axcelis Asia Operations Center facility in South Korea brings production capability closer to our Asia-based customers. Our state-of-the-art 98,500 square foot logistics and flex manufacturing center in Beverly, Massachusetts became fully operational in the third quarter of 2023. 10 Table of Contents Operating lease expense and depreciation and interest expense relating to our finance lease obligation are recognized within our consolidated statement of operations for the three and nine months ended September 30, 2023 and 2022 as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ ​ ​ September 30, ​ September 30, ​ ​ Lease cost Classification ​ 2023 2022 2023 2022 ​ Operating lease cost ​ ​ (in thousands) ​ Product / services* Cost of revenue ​ $ 2,041 ​ $ 1,462 ​ $ 5,328 ​ $ 3,978 ​ ​ Research and development Operating expenses ​ 183 ​ 54 ​ 426 ​ 186 ​ ​ Sales and marketing* Operating expenses ​ 419 ​ 369 ​ 1,231 ​ 1,155 ​ ​ General and administrative* Operating expenses ​ 298 ​ 253 ​ 813 ​ 773 ​ ​ Total operating lease cost ​ ​ $ 2,941 ​ $ 2,138 ​ $ 7,798 ​ $ 6,092 ​ ​ Finance lease cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation of leased assets Cost of revenue, Research and development, Sales and marketing and General and administrative ​ $ 324 ​ $ 325 ​ $ 961 ​ $ 973 ​ ​ Interest on lease liabilities Interest expense ​ 1,214 ​ 1,245 ​ 3,668 ​ 3,754 ​ ​ Total finance lease cost ​ ​ $ 1,538 ​ $ 1,570 ​ $ 4,629 ​ $ 4,727 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total lease cost ​ ​ $ 4,479 ​ $ 3,708 ​ $ 12,427 ​ $ 10,819 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ * Product / services, sales and marketing and general and administrative expense also includes short-term lease and variable lease costs of approximately $ 0.6 million and $ 1.6 million for the three and nine months ended September 30, 2023, respectively, and includes short-term lease and variable lease costs of approximately $ 0.4 million and $ 1.4 million for the three and nine months ended September 30, 2022, respectively. ​ ​ ​ ​ The lease of our corporate headquarters, shown below under finance leases, had an original lease term of 22 years , beginning in January 2015 and expiring in January 2037, with renewal options. All other locations are treated as operating leases, with lease terms ranging from one to sixteen years . The tables below reflect the minimum cash outflow regarding our current lease obligations as well as the weighted-average remaining lease term and weighted-average discount rates used in our calculation of our lease obligations and right-of-use assets as of September 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance ​ Operating Total Maturity of Lease Liabilities ​ Leases ​ Leases ​ Leases ​ ​ ​ (in thousands) ​ 2023 ​ $ 1,531 ​ $ 2,117 ​ $ 3,648 ​ 2024 ​ 6,252 ​ 6,248 ​ 12,500 ​ 2025 ​ 5,930 ​ 4,761 ​ 10,691 ​ 2026 ​ 6,008 ​ 3,471 ​ 9,479 ​ 2027 ​ ​ 6,128 ​ ​ 2,502 ​ ​ 8,630 ​ Thereafter ​ ​ 61,586 ​ ​ 25,123 ​ ​ 86,709 ​ Total lease payments ​ $ 87,435 ​ $ 44,222 ​ $ 131,657 ​ Less interest portion* ​ ​ ( 41,927 ) ​ ​ ( 13,371 ) ​ ​ ( 55,298 ) ​ Finance lease and operating lease obligations ​ $ 45,508 ​ $ 30,851 ​ $ 76,359 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ * Finance lease interest calculated using the implied interest rate; operating lease interest calculated using estimated corporate borrowing rate. ​ ​ The table above does not include options to renew lease terms that are not reasonably certain of being exercised. ​ 11 Table of Contents ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ Lease term and discount rate 2023 ​ Weighted-average remaining lease term (years): ​ ​ ​ ​ Operating leases ​ ​ 11.6 ​ Finance leases ​ 13.3 ​ Weighted-average discount rate: ​ ​ ​ ​ Operating leases ​ 5.5 % ​ Finance leases ​ 10.5 % ​ ​ ​ ​ ​ ​ ​ Our cash outflows from our operating leases include rent expense and other charges associated with these leases. These cash flows are included within the operating activities section of our statement of cash flows. Our cash flows from our finance lease include both an interest component and a principal component. The table below shows our cash outflows by lease type and related section of our statement of cash flows, as well as the non-cash amount capitalized on our balance sheet in relation to our operating lease right-of-use assets for the nine months ended September 30, 2023 and 2022, respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, ​ Cash paid for amounts included in the measurement of lease liabilities 2023 2022 ​ ​ ​ (in thousands) ​ Operating cash outflows from operating leases ​ $ 7,798 ​ $ 6,092 ​ Operating cash outflows from finance leases ​ 3,668 ​ 3,754 ​ Financing cash outflows from finance leases ​ 915 ​ 728 ​ Operating lease assets obtained in exchange for operating lease liabilities ​ 25,697 ​ 5,494 ​ Finance lease assets obtained in exchange for new finance lease liabilities ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Note 4. Revenue ​ To reflect the organization of our business operations, we divide revenue into two categories: revenue from sales of new systems and revenue arising from the sale of used systems, parts and labor to customers who own systems, which we refer to as “Aftermarket.” ​ Revenue by categories used by management are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ September 30, ​ September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ ​ (in thousands) Systems ​ $ 231,454 ​ $ 171,092 ​ $ 641,825 ​ $ 488,243 Aftermarket ​ ​ 60,872 ​ ​ 58,083 ​ ​ 178,491 ​ ​ 165,704 Total Revenue ​ $ 292,326 ​ $ 229,175 ​ $ 820,316 ​ $ 653,947 ​ 12 Table of Contents We also consider revenue by geography. Revenue is allocated to geographic markets based upon the location to which our products are shipped and in which our services are performed. Revenue in our principal geographic markets is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ September 30, ​ September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ ​ (in thousands) North America ​ $ 51,563 ​ $ 36,036 ​ $ 134,647 ​ $ 95,633 Asia Pacific ​ ​ 185,194 ​ ​ 166,342 ​ ​ 582,238 ​ ​ 484,286 Europe ​ ​ 55,569 ​ ​ 26,797 ​ ​ 103,431 ​ ​ 74,028 Total Revenue ​ $ 292,326 ​ $ 229,175 ​ $ 820,316 ​ $ 653,947 ​ Our system sales revenue transactions give rise to contract liabilities (in the case of pre-payments and the fair value of goods and services to be delivered after the system delivery, such as installation and certain warranty obligations). ​ Contract liabilities are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 ​ ​ (in thousands) Contract liabilities ​ $ 202,029 ​ $ 154,777 ​ ​ ​ ​ ​ ​ ​ Contract liabilities are reflected as deferred revenue on the consolidated balance sheet and relate to payments invoiced or received in advance of completion of performance obligations under a contract. Contract liabilities are recognized as revenue upon the fulfillment of performance obligations. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ September 30, September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ ​ (in thousands) Balance, beginning of the period ​ $ 182,540 ​ $ 71,549 ​ $ 154,777 ​ $ 68,436 Deferral of revenue ​ ​ 62,787 ​ ​ 70,706 ​ ​ 154,216 ​ ​ 108,472 Recognition of deferred revenue ​ ​ ( 43,298 ) ​ ​ ( 19,666 ) ​ ​ ( 106,964 ) ​ ​ ( 54,319 ) Balance, end of the period ​ $ 202,029 ​ $ 122,589 ​ $ 202,029 ​ $ 122,589 ​ The majority of our system transactions have either (1) payment terms of 90 % due upon shipment of the system and 10 % due upon acceptance or (2) a pre-shipment deposit ranging from 20 % to 60 %, 70 % to 30 % due upon shipment and 10 % at acceptance. Aftermarket transaction payment terms typically provide that payment is due either within 30 or 60 days after the service is provided or parts delivered. ​ Note 5. Receivables and Allowances for Credit Losses ​ All trade receivables are reported on the consolidated balance sheets at their amortized cost adjusted for any write-offs and net of allowances for credit losses. ​ We maintain an allowance for credit losses, which represents an estimate of expected losses over the remaining contractual life of our receivables, considering current market conditions and estimates for supportable forecasts when appropriate. The estimate is a result of our ongoing assessments and evaluations of collectability, historical loss experience, and future expectations in estimating credit losses in our receivable portfolio. We use historical loss experience rates and apply them to a related aging analysis while also considering customer and/or economic risk where appropriate. Determination of the proper amount of allowances requires management to exercise judgment about the timing, frequency and severity of credit losses that could materially affect the provision for credit losses and, as a result, net earnings. The allowance takes into consideration numerous quantitative and qualitative factors that include receivable type, historical loss 13 Table of Contents experience, loss migration, delinquency trends, collection experience, current economic conditions, trade restrictions, estimates for supportable forecasts, when appropriate, and credit risk characteristics. ​ We evaluate the credit risk of the customer when extending credit based on a combination of financial and qualitative factors that may affect our customers’ ability to pay. These factors may include the customer’s financial condition, past payment experience, and credit bureau report, as well as the value of the underlying collateral. ​ Management performs detailed reviews of our receivables on a quarterly basis to assess the adequacy of the allowances and to determine if any impairment has occurred. Amounts determined to be uncollectable are charged directly against the allowances, while amounts recovered on previously written-off accounts increase the allowances. Changes to the allowances for credit losses are maintained through adjustments to the provision for credit losses, which are charged to current period earnings. We recorded $ 0.7 million in bad debt expense for the three and nine-month periods ended September 30, 2023. We did not have any allowance or incur any credit losses or recoveries for the three and nine-month periods ended September 30, 2022. As of September 30, 2023 and 2022, respectively, we had no provision for credit losses. ​ ​ Note 6. Computation of Net Earnings per Share ​ Basic earnings per share is computed by dividing income available to common stockholders (the numerator) by the weighted-average number of shares of common stock outstanding (the denominator) for the period. The computation of diluted earnings per share is similar to basic earnings per share, except that the denominator is increased by the number of additional shares of common stock that would have been outstanding if the potentially dilutive shares of common stock issuable on exercise of stock options and vesting of RSUs had been issued, calculated using the treasury stock method. ​ The components of net earnings per share are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2023 2022 2023 2022 ​ ​ (in thousands, except per share amounts) ​ Net income available to common stockholders ​ $ 65,931 ​ $ 40,283 ​ $ 175,207 ​ $ 126,087 ​ Weighted average shares of common stock outstanding used in computing basic income per share ​ 32,807 ​ 33,011 ​ 32,775 ​ 33,116 ​ Incremental options and RSUs ​ 352 ​ 378 ​ 433 ​ 522 ​ Weighted average shares of common stock used in computing diluted net income per share ​ 33,159 ​ 33,389 ​ 33,208 ​ 33,638 ​ Net income per share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ $ 2.01 ​ $ 1.22 ​ $ 5.35 ​ $ 3.81 ​ Diluted ​ $ 1.99 ​ $ 1.21 ​ $ 5.28 ​ $ 3.75 ​ ​ ​ Diluted weighted average shares of common stock outstanding does not include 734 and 5,046 common equivalent shares issuable with respect to outstanding equity awards for the three-month periods ended September 30, 2023 and 2022, respectively, or 2,598 and 6,692 common equivalent shares issuable with respect to outstanding equity awards for the nine-month periods ended September 30, 2023 and 2022, respectively, as their effect would have been anti-dilutive. ​ ​ Note 7. Accumulated Other Comprehensive Loss ​ The following table presents the changes in accumulated other comprehensive loss, net of tax, by component, for the nine months ended September 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign Defined benefit ​ ​ ​ ​ currency ​ pension plan ​ Total ​ ​ (in thousands) Balance at December 31, 2022 ​ $ ( 1,994 ) ​ $ 26 ​ $ ( 1,968 ) ​ Other comprehensive loss and pension reclassification ​ ( 2,192 ) ​ — ​ ( 2,192 ) ​ Balance at September 30, 2023 ​ $ ( 4,186 ) ​ $ 26 ​ $ ( 4,160 ) ​ ​ 14 Table of Contents ​ ​ Note 8. Cash, cash equivalents and restricted cash ​ The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets to the total of the amounts shown in the statement of cash flows: ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ ​ 2022 ​ ​ (in thousands) ​ Cash and cash equivalents $ 142,300 ​ $ 185,595 ​ Long-term restricted cash ​ 6,650 ​ ​ 752 ​ Total cash, cash equivalents and restricted cash $ 148,950 ​ $ 186,347 ​ ​ As of September 30, 2023, we had $ 6.7 million in restricted cash representing the total of (i) a $ 5.9 million cash collateral relating to our lease for our headquarters in Beverly, Massachusetts, (ii) a $ 0.7 million letter of credit relating to workers’ compensation insurance and (iii) a $ 0.1 million deposit relating to customs activity. See Note 12 for further discussion on the $ 5.9 million cash collateral. ​ Note 9. Inventories, net ​ The components of inventories are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2023 2022 ​ ​ (in thousands) ​ Raw materials ​ $ 226,601 ​ $ 187,313 ​ Work in process ​ 55,825 ​ 35,069 ​ Finished goods (completed systems) ​ 29,797 ​ 20,024 ​ Inventories, net ​ $ 312,223 ​ $ 242,406 ​ ​ When recorded, inventory reserves reduce the carrying value of inventories to their net realizable value. We establish inventory reserves when conditions exist that indicate inventory may be in excess of anticipated demand or is obsolete based upon assumptions about future demand for the Company’s products or market conditions. We regularly evaluate the ability to realize the value of inventories based on a combination of factors including the following: forecasted sales or usage, estimated product end of life dates, estimated current and future market value and new product introductions. Purchasing and usage alternatives are also explored to mitigate inventory exposure. ​ Note 10. Product Warranty ​ We generally offer a one-year warranty for all of our systems, the terms and conditions of which vary depending upon the product sold. For all systems sold, we accrue a liability for the estimated cost of standard warranty at the time of system shipment and defer the portion of systems revenue attributable to the fair value of non-standard warranty. Costs for non-standard warranty are expensed as incurred. Factors that affect our warranty liability include the number of installed units, historical and anticipated product failure rates, material usage and service labor costs. We periodically assess the adequacy of our recorded liability and adjust the amount as necessary. ​ 15 Table of Contents The changes in our standard product warranty liability are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended ​ ​ ​ September 30, ​ ​ 2023 2022 ​ ​ (in thousands) ​ Balance at January 1 (beginning of year) ​ $ 10,487 ​ $ 6,924 ​ Warranties issued during the period ​ 9,072 ​ 7,454 ​ Settlements made during the period ​ ( 7,746 ) ​ ( 4,633 ) ​ Changes in estimate of liability for pre-existing warranties during the period ​ 2,043 ​ ( 78 ) ​ Balance at September 30 (end of period) ​ $ 13,856 ​ $ 9,667 ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount classified as current ​ $ 11,464 ​ $ 8,482 ​ Amount classified as long-term (within other long-term liabilities) ​ 2,392 ​ 1,185 ​ Total warranty liability ​ $ 13,856 ​ $ 9,667 ​ ​ ​ Note 11. Fair Value Measurements ​ Fair value is defined as the price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. ​ (a) Fair Value Hierarchy ​ The accounting guidance for fair value measurement requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard establishes a fair value hierarchy based on the level of independent, objective evidence surrounding the inputs used to measure fair value. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The fair value hierarchy is as follows: ​ Level 1 - applies to assets or liabilities for which there are quoted prices in active markets for identical assets or liabilities. ​ Level 2 - applies to assets or liabilities for which there are inputs other than quoted prices that are observable for the asset or liability, such as quoted prices for similar assets or liabilities in active markets; quoted prices for identical assets or liabilities in markets with insufficient volume or infrequent transactions (less active markets); or model-derived valuations in which significant inputs are observable or can be derived principally from, or corroborated by, observable market data. ​ Level 3 - applies to assets or liabilities for which there are unobservable inputs to the valuation methodology that are significant to the measurement of the fair value of the assets or liabilities. ​ (b) Fair Value Measurements ​ Our money market funds and short-term investments with initial maturities of three months or less are included in cash and cash equivalents in the consolidated balance sheets. Other investments that have a maturity of greater than three months but less than one year are included within short-term investments in the consolidated balance sheets. ​ 16 Table of Contents The following table sets forth our assets by level within the fair value hierarchy: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ ​ Fair Value Measurements ​ Level 1 Level 2 Level 3 Total ​ ​ (in thousands) Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents and other short-term investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents (money market funds, U.S. Government Securities and Agency Investments) ​ $ 114,475 ​ $ — ​ $ — ​ $ 114,475 ​ Short-term investments (U.S. Government Securities and Agency Investments) ​ ​ 318,202 ​ ​ — ​ ​ — ​ ​ 318,202 ​ Total ​ $ 432,677 ​ $ — ​ $ — ​ $ 432,677 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Fair Value Measurements ​ Level 1 Level 2 Level 3 Total ​ ​ (in thousands) Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents and other short-term investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents (money market funds, U.S. Government Securities and Agency Investments) ​ $ 111,771 ​ $ 25,000 ​ $ — ​ $ 136,771 ​ Short-term investments (U.S. Government Securities and Agency Investments) ​ ​ 245,247 ​ ​ — ​ ​ — ​ ​ 245,247 ​ Total ​ $ 357,018 ​ $ 25,000 ​ $ — ​ $ 382,018 ​ ​ (c) Other Financial Instruments ​ The carrying amounts reflected in the consolidated balance sheets for accounts receivable, prepaid expenses and other current assets and non-current assets, restricted cash, accounts payable and accrued expenses approximate fair value due to their short-term maturities. ​ Note 12. Financing Arrangements ​ On January 30, 2015, we sold our corporate headquarters facility in Beverly, Massachusetts for $ 48.9 million. As part of the sale, we also entered into a 22-year lease agreement of our headquarters facility. This sale-leaseback is accounted for as a financing lease under generally accepted accounting principles and, as such, we have recorded a financing obligation of $ 45.5 million as of September 30, 2023. The associated lease payments include both an interest component and payment of principal, with the remaining liability being extinguished at the end of the original lease term. As of September 30, 2023, we had a security deposit of $ 5.9 million related to this lease. ​ On April 5, 2023 we terminated the Senior Secured Credit Facilities Credit Agreement, as amended (the “Credit Agreement”), with Silicon Valley Bank that we entered into on July 31, 2020. The Credit Agreement provided for a revolving credit facility covering borrowings and letters of credit in an aggregate principal amount not to exceed $ 40.0 million. Our obligations under the Credit Agreement were secured by a security interest, senior to any current and future debts and to any security interest, in all of our rights, title, and interest in, to and under substantially all of our assets, subject to limited exceptions, including permitted liens. Upon termination, these liens and all other obligations under the credit agreement, were released. A letter of credit issued by Silicon Valley Bank, a division of First Citizens Bank & Trust Company (successor by purchase to the Federal Deposit Insurance Corporation as Receiver for Silicon Valley Bridge Bank, N.A.) as successor to Silicon Valley Bank, remains outstanding in the amount of $ 5.9 million, securing our lease on our corporate headquarters. This letter of credit was transitioned to a cash collateral arrangement on March 30, 2023, and was classified as long-term restricted cash on our balance sheet at September 30, 2023. ​ Note 13. Income Taxes ​ Income tax expense was $ 7.7 million for the three months ended September 30, 2023, compared to $ 4.7 million for the three months ended September 30, 2022. The $ 3.0 million increase was primarily due to an increase in pre-tax 17 Table of Contents income partially offset by the tax deduction related to foreign sales taxed at a lower rate. Income tax expense was $ 16.0 million for the nine months ended September 30, 2023, compared to $ 13.0 million for the nine months ended September 30, 2022. The $ 3.0 million increase was primarily due to an increase in pre-tax income partially offset by the tax deduction related to stock based compensation and additional research and development tax credit. ​ The effective tax rate for the three and nine months ended September 30, 2023 was less than the U.S. statutory rate of 21 % due to a forecasted Foreign Derived Intangible Income deduction, Federal research and development tax credits and a favorable discrete item related to equity compensation that reduces the annual tax rate. ​ The deferred income taxes of $ 44.3 million and $ 31.7 million as of September 30, 2023 and December 31, 2022, respectively, reflect the net tax effect of temporary differences between the carrying amount of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes, as well as the tax effect of carryforwards. As of September 30, 2023, we have recorded a $ 10.6 million valuation allowance in the U.S. against certain tax credits and state net operating losses due to the uncertainty of their realization. Realization of our net deferred tax assets is dependent on future taxable income. We believe it is more likely than not that such assets will be realized; however, ultimate realization could be impacted by market conditions and other variables not known or anticipated at this time. ​ Note 14. Concentration of Risk ​ For the three months ended September 30, 2023, no individual customer accounted for greater than ten percent of total revenue. For the three months ended September 30, 2022, one customer accounted for 13.8 % of total revenue. ​ For the nine months ended September 30, 2023, one customer accounted for 10.7 % of total revenue. For the nine months ended September 30, 2022, one customer accounted for 14.8 % of total revenue. ​ At September 30, 2023, three customers accounted for 11.8 %, 11.0 %, and 10.2 % of accounts receivable, respectively. At December 31, 2022, two customers accounted for 19.4 % and 11.5 % of accounts receivable, respectively. ​ Note 15. Share Repurchase ​ In February 2022, our Board of Directors approved stock repurchases of up to $ 100 million of our common stock. In August 2023, our Board of Directors approved additional funding of $ 200 million for our stock repurchase program, to be available on full utilization of the $ 100 million repurchase funding approved in February 2022. During the nine months ended September 30, 2023, we repurchased 0.3 million shares at an average cost of $ 137.54 per share. The timing and actual number of any additional shares to be repurchased under this program will depend on various factors including price, corporate and regulatory requirements, alternative investment opportunities and other market conditions. ​ Repurchased shares are accounted for when the transaction is settled and returned to the status of authorized but unissued shares. Accordingly, on our balance sheet, the repurchase price is deducted from common stock par value and from additional paid-in capital for the excess over par value. If additional paid-in capital has been exhausted, the excess over par value is deducted from retained earnings. Direct costs incurred to acquire the shares are included in the total cost of the shares. ​ Note 16. Contingencies ​ (a) Litigation ​ We are from time to time a party to litigation that arises in the normal course of our business operations. We are not presently a party to any litigation that we believe might have a material adverse effect on our business operations. ​ (b) Indemnifications ​ Our system sales agreements typically include provisions under which we agree to take certain actions, provide certain remedies and defend our customers against third-party claims of intellectual property infringement under specified conditions and indemnify customers against any damage and costs awarded in connection with such claims. We have not incurred any material costs as a result of such indemnifications and have not accrued any liabilities related to such obligations in the accompanying consolidated financial statements. 18 Table of Contents