Axcelis Technologies Inc (ACLS) shareholders
ACLSNasdaqSpecial Industry Machinery, NECFiscal year ends December 31
Financials through Q3 FY2026, quarter ended Sep 30, 2026Last filing: 10-Q on Nov 5, 2026Score 6/3043% above fair value
$104.42−3.64 (-3.37%)
Close on Nov 13, 2026Market cap $3.22BP/E 31.1Yield –
Ownership
Institutional holdings as of Jun 30, 2026, from 13F filings
Held by institutions
100.0%
31M of 31M shares
Institutional holders
440
114 new, 46 sold out
Net institutional buying
-1M
In Q2 2026
Insider trades, 12 months
0 buys · 23 sales
Net sold $6.42M
Shares held by institutions
Holders of more than 5%
Latest Schedule 13D (active) or 13G (passive) filed by each holder
| Holder | Shares | % of class | Filing | As of |
|---|---|---|---|---|
| BlackRock, Inc. | 4,911,042 | 15.30% | 13G (passive) amendment | Mar 31, 2025 |
| FMR LLC Joint filing with Abigail P. Johnson (13.40%) | 4,122,402 | 13.40% | 13G (passive) amendment | Jun 30, 2026 |
| Abigail P. Johnson Joint filing with FMR LLC (11.40%) | 3,521,264 | 11.40% | 13G (passive) amendment | Sep 30, 2026 |
| Vanguard Portfolio Management | 2,501,359 | 8.14% | 13G (passive) | Mar 31, 2026 |
| American Century Companies, Inc. Joint filing with American Century Investment Management, Inc. (5.20%), Stowers Institute for Medical Research (5.20%) | 1,659,463 | 5.20% | 13G (passive) | Jun 30, 2025 |
| Vanguard Capital Management | 1,617,321 | 5.26% | 13G (passive) | Mar 31, 2026 |
Top institutional holders
13F holdings as of Jun 30, 2026
| Holder | Shares | % of ACLS | Value | Change | % of portfolio |
|---|---|---|---|---|---|
| BlackRock, Inc. | 5,029,462 | 16.29% | $952.83M | +92,688 | 0.01% |
| FMR LLC | 4,125,902 | 13.36% | $781.65M | +1,694,781 | 0.03% |
| Vanguard Portfolio Management LLC | 2,478,878 | 8.03% | $469.62M | −9,415 | 0.02% |
| Vanguard Capital Management LLC | 1,386,518 | 4.49% | $262.68M | +3,748 | 0.01% |
| State Street Corp | 1,231,109 | 3.99% | $233.18M | +42,064 | 0.01% |
| Victory Capital Management Inc | 1,134,007 | 3.67% | $214.84M | −144,998 | 0.12% |
| Reinhart Partners, LLC. | 928,660 | 3.01% | $175.94M | −729,085 | 4.02% |
| Geode Capital Management, LLC | 833,607 | 2.70% | $157.96M | +22,343 | 0.01% |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. | 803,151 | 2.60% | $152.16M | −202,877 | 0.15% |
| Dimensional Fund Advisors LP | 709,266 | 2.30% | $134.35M | −134,831 | 0.02% |
| Balyasny Asset Management L.P. | 616,196 | 2.00% | $116.74M | −748,344 | 0.15% |
| Primecap Management Co/Ca/ | 610,451 | 1.98% | $115.65M | −48,201 | 0.07% |
| Invesco Ltd. | 527,724 | 1.71% | $99.98M | +362,649 | 0.01% |
| Charles Schwab Investment Management Inc | 416,230 | 1.35% | $78.85M | −29,539 | 0.01% |
| Price T Rowe Associates Inc /Md/ | 394,455 | 1.28% | $74.73M | +32,253 | 0.01% |
| Barrow Hanley Mewhinney & Strauss LLC | 392,240 | 1.27% | $74.31M | +392,183 | 0.23% |
| Manufacturers Life Insurance Company, The | 383,760 | 1.24% | $72.70M | −107,985 | 0.06% |
| Northern Trust Corp | 382,027 | 1.24% | $72.38M | −34,676 | 0.01% |
| American Century Companies Inc | 369,879 | 1.20% | $70.07M | −582,035 | 0.03% |
| Morgan Stanley | 366,077 | 1.19% | $69.35M | −215,559 | 0.00% |
Institutional buying and selling by quarter
Positions opened, added to, reduced and closed by 13F filers
| Quarter | Holders | Shares held | % of shares | New / added | Reduced / closed | Shares bought | Shares sold |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 440 | 31M | 100.0% | 114 / 119 | 143 / 46 | 5M | 6M |
| Q1 2026 | 379 | 33M | 100.0% | 70 / 100 | 134 / 59 | 10M | 4M |
| Q4 2025 | 372 | 31M | 100.0% | 67 / 121 | 121 / 51 | 4M | 3M |
| Q3 2025 | 361 | 31M | 99.2% | 74 / 107 | 121 / 38 | 3M | 4M |
| Q2 2025 | 329 | 32M | 100.0% | 65 / 108 | 106 / 41 | 4M | 4M |
| Q1 2025 | 306 | 31M | 100.0% | 50 / 124 | 87 / 66 | 4M | 4M |
| Q4 2024 | 324 | 31M | 100.0% | 59 / 125 | 93 / 100 | 5M | 5M |
| Q3 2024 | 368 | 30M | 98.6% | 57 / 130 | 126 / 77 | 9M | 4M |
| Q2 2024 | 391 | 31M | 99.9% | 64 / 141 | 127 / 52 | 4M | 5M |
| Q1 2024 | 383 | 32M | 100.0% | 58 / 116 | 163 / 95 | 5M | 4M |
| Q4 2023 | 421 | 30M | 98.6% | 72 / 163 | 130 / 65 | 5M | 5M |
| Q3 2023 | 420 | 30M | 95.8% | 65 / 148 | 153 / 47 | 3M | 3M |
Top mutual fund and ETF holders
Latest monthly portfolio reports (Form N-PORT)
363 funds held ACLS in Q2 2026, 49% of their shares through ETFs. Each fund counts once per quarter, from its quarter-end report.
| Fund | Shares | % of ACLS | Value | % of fund | As of |
|---|---|---|---|---|---|
| iShares Core S&P Small-Cap ETF | 1,851,581 | 6.00% | $350.78M | 0.32% | Jun 30, 2026 |
| Vanguard Total Stock Market Index Fund | 976,851 | 3.16% | $185.06M | 0.01% | Jun 30, 2026 |
| iShares Russell 2000 ETF | 805,510 | 2.61% | $152.60M | 0.18% | Jun 30, 2026 |
| Vanguard Information Technology Index Fund | 780,738 | 2.53% | $117.43M | 0.07% | May 31, 2026 |
| Vanguard Small-Cap Index Fund | 704,939 | 2.28% | $133.55M | 0.07% | Jun 30, 2026 |
| PRIMECAP Odyssey Aggressive Growth Fund | 575,146 | 1.86% | $74.99M | 1.01% | Jul 31, 2026 |
| Vanguard Small-Cap Value Index Fund | 446,494 | 1.45% | $84.59M | 0.12% | Jun 30, 2026 |
| Fidelity Contrafund | 412,405 | 1.34% | $78.13M | 0.04% | Jun 30, 2026 |
| Fidelity Stock Selector Small Cap Fund | 353,907 | 1.15% | $46.14M | 0.63% | Jul 31, 2026 |
| Vanguard Extended Market Index Fund | 352,333 | 1.14% | $66.75M | 0.07% | Jun 30, 2026 |
| Fidelity Small Cap Index Fund | 343,166 | 1.11% | $44.74M | 0.13% | Jul 31, 2026 |
| Strategic Advisers Fidelity U.S. Total Stock Fund | 314,000 | 1.02% | $47.23M | 0.02% | May 31, 2026 |
| iShares Russell 2000 Growth ETF | 289,688 | 0.94% | $54.88M | 0.36% | Jun 30, 2026 |
| State Street(R) SPDR(R) Portfolio S&P 600(TM) Small Cap ETF | 281,637 | 0.91% | $53.36M | 0.32% | Jun 30, 2026 |
| Fidelity Small Cap Discovery Fund | 280,725 | 0.91% | $36.60M | 1.61% | Jul 31, 2026 |
Officers, directors and major owners
People who filed Forms 3, 4 or 5 in the last two years
| Name | Role | Shares owned | % of shares | Latest filing |
|---|---|---|---|---|
| Russell Low | PRESIDENT AND CEO, Director | 154,900 | 0.50% | May 20, 2026 |
| Jeroen Delsman | EVP and CFO | – | – | Nov 12, 2026 |
| Greg Redinbo | EVP and Chief Strategy Officer | 34,816 | 0.11% | Sep 16, 2026 |
| Christopher Tatnall | EVP Global Customer Operations | 27,491 | 0.09% | Sep 16, 2026 |
| David Ryzhik | SVP Interim CFO | 9,790 | 0.03% | Jul 17, 2026 |
| Gerald M. Blumenstock | EVP, Research, Dev. & Eng. | 19,987 | 0.06% | Jun 16, 2026 |
| Robert John Mahoney | EVP Global Operations | 14,410 | 0.05% | Jun 3, 2026 |
| Todd Sutton | VP Corporate Controller | 6,360 | 0.02% | May 28, 2026 |
| Eileen Evans | EVP, General Counsel and Sec'y | 31,295 | 0.10% | May 22, 2026 |
| James Gordon Coogan | EVP AND CFO | 37,144 | 0.12% | Mar 3, 2026 |
| Lynnette C. Fallon | EXECUTIVE VP, HR/LEGAL | 27,323 | 0.09% | Jan 7, 2025 |
| Necip Sayiner | Director | 7,112 | 0.02% | Jun 4, 2026 |
| Dennis Thomas St | Director | 17,695 | 0.06% | May 26, 2026 |
| Gregory B. Graves | Director | 5,473 | 0.02% | May 20, 2026 |
| John T. Kurtzweil | Director | 32,990 | 0.11% | May 20, 2026 |
| Jeanne Quirk | Director | 11,400 | 0.04% | May 20, 2026 |
| Tzu Yin Chiu | Director | 11,843 | 0.04% | May 18, 2026 |
| Jorge Titinger | Director | 5,917 | 0.02% | May 18, 2026 |
Insider trades
Common stock transactions reported on Form 4, newest first
| Insider | Date | Transaction | Shares | Price | Value | Shares after |
|---|---|---|---|---|---|---|
| Christopher Tatnall EVP Global Customer Operations | Sep 15, 2026 | Tax withholding | −136 | $105.04 | $14.29K | 27,491 |
| Greg Redinbo EVP and Chief Strategy Officer | Sep 15, 2026 | Tax withholding | −208 | $105.04 | $21.85K | 34,816 |
| David Ryzhik SVP Interim CFO | Jul 15, 2026 | Tax withholding | −94 | $145.01 | $13.63K | 9,790 |
| David Ryzhik SVP Interim CFO | Jul 15, 2026 | Tax withholding | −127 | $145.01 | $18.42K | 9,884 |
| David Ryzhik SVP Interim CFO | Jun 16, 2026 | Tax withholding | −76 | $176.85 | $13.44K | 9,955 |
| Gerald M. Blumenstock EVP, Research, Dev. & Eng. | Jun 15, 2026 | Tax withholding | −506 | $191.60 | $96.95K | 19,987 |
| Necip Sayiner Director | Jun 3, 2026 | Sale | −1,586 | $157.44 | $249.70K | 7,112 |
| Robert John Mahoney EVP Global Operations | Jun 2, 2026 | Sale | −1,155 | $155.24 | $179.30K | 14,410 |
| Todd Sutton VP Corporate Controller | May 27, 2026 | Sale | −2,000 | $159.99 | $319.98K | 6,360 |
| Dennis Thomas St Director | May 22, 2026 | Sale | −900 | $155.37 | $139.83K | 17,695 |
| Eileen Evans EVP, General Counsel and Sec'y | May 22, 2026 | Sale | −926 | $155.51 | $144.00K | 31,295 |
| Gerald M. Blumenstock EVP, Research, Dev. & Eng. | May 21, 2026 | Sale | −1,161 | $152.70 | $177.28K | 20,493 |
| Christopher Tatnall EVP Global Customer Operations | May 20, 2026 | Sale | −1,166 | $149.75 | $174.61K | 27,627 |
| Gregory B. Graves Director | May 19, 2026 | Sale | −600 | $142.51 | $85.51K | 5,473 |
| Gregory B. Graves Director | May 19, 2026 | Sale | −2,625 | $141.41 | $371.20K | 6,073 |
| Jeanne Quirk Director | May 19, 2026 | Sale | −1,789 | $140.22 | $250.85K | 11,400 |
| John T. Kurtzweil Director | May 19, 2026 | Sale | −3,500 | $138.79 | $485.77K | 32,990 |
| Russell Low PRESIDENT AND CEO, Director | May 18, 2026 | Tax withholding | −711 | $146.24 | $103.98K | 154,900 |
| Robert John Mahoney EVP Global Operations | May 18, 2026 | Tax withholding | −182 | $146.24 | $26.62K | 15,695 |
| Robert John Mahoney EVP Global Operations | May 18, 2026 | Tax withholding | −130 | $146.24 | $19.01K | 15,565 |
| Greg Redinbo EVP MARKETING AND APPLICATIONS | May 18, 2026 | Tax withholding | −111 | $146.24 | $16.23K | 35,103 |
| Greg Redinbo EVP MARKETING AND APPLICATIONS | May 18, 2026 | Tax withholding | −79 | $146.24 | $11.55K | 35,024 |
| Todd Sutton VP Corporate Controller | May 18, 2026 | Tax withholding | −184 | $146.24 | $26.91K | 8,360 |
| Christopher Tatnall EVP Global Customer Operations | May 15, 2026 | Award | +3,504 | – | – | 26,548 |
| Christopher Tatnall EVP Global Customer Operations | May 15, 2026 | Tax withholding | −345 | $155.18 | $53.54K | 28,963 |
| Christopher Tatnall EVP Global Customer Operations | May 15, 2026 | Tax withholding | −170 | $155.18 | $26.38K | 28,793 |
| Christopher Tatnall EVP Global Customer Operations | May 15, 2026 | Tax withholding | −744 | $155.18 | $115.45K | 29,308 |
| Christopher Tatnall EVP Global Customer Operations | May 15, 2026 | Award | +3,504 | – | – | 30,052 |
| David Ryzhik SVP Interim CFO | May 15, 2026 | Tax withholding | −226 | $155.18 | $35.07K | 10,031 |
| David Ryzhik SVP Interim CFO | May 15, 2026 | Award | +3,115 | – | – | 10,257 |
| Greg Redinbo EVP MARKETING AND APPLICATIONS | May 15, 2026 | Tax withholding | −210 | $155.18 | $32.59K | 35,391 |
| Greg Redinbo EVP MARKETING AND APPLICATIONS | May 15, 2026 | Award | +3,115 | – | – | 36,053 |
| Greg Redinbo EVP MARKETING AND APPLICATIONS | May 15, 2026 | Tax withholding | −452 | $155.18 | $70.14K | 35,601 |
| Greg Redinbo EVP MARKETING AND APPLICATIONS | May 15, 2026 | Tax withholding | −177 | $155.18 | $27.47K | 35,214 |
| Greg Redinbo EVP MARKETING AND APPLICATIONS | May 15, 2026 | Award | +3,115 | – | – | 32,938 |
| Gerald M. Blumenstock EVP, Research, Dev. & Eng. | May 15, 2026 | Award | +2,725 | – | – | 20,018 |
| Gerald M. Blumenstock EVP, Research, Dev. & Eng. | May 15, 2026 | Award | +2,725 | – | – | 22,743 |
| Gerald M. Blumenstock EVP, Research, Dev. & Eng. | May 15, 2026 | Tax withholding | −345 | $155.18 | $53.54K | 21,654 |
| Gerald M. Blumenstock EVP, Research, Dev. & Eng. | May 15, 2026 | Tax withholding | −744 | $155.18 | $115.45K | 21,999 |
| Todd Sutton VP Corporate Controller | May 15, 2026 | Award | +1,168 | – | – | 8,985 |
| Todd Sutton VP Corporate Controller | May 15, 2026 | Tax withholding | −103 | $155.18 | $15.98K | 8,544 |
| Todd Sutton VP Corporate Controller | May 15, 2026 | Tax withholding | −112 | $155.18 | $17.38K | 8,647 |
| Todd Sutton VP Corporate Controller | May 15, 2026 | Tax withholding | −226 | $155.18 | $35.07K | 8,759 |
| Eileen Evans EVP, General Counsel and Sec'y | May 15, 2026 | Award | +3,893 | – | – | 33,088 |
| Eileen Evans EVP, General Counsel and Sec'y | May 15, 2026 | Tax withholding | −867 | $155.18 | $134.54K | 32,221 |
| Eileen Evans EVP, General Counsel and Sec'y | May 15, 2026 | Award | +3,893 | – | – | 29,195 |
| Russell Low PRESIDENT AND CEO, Director | May 15, 2026 | Award | +19,466 | – | – | 143,036 |
| Russell Low PRESIDENT AND CEO, Director | May 15, 2026 | Award | +19,466 | – | – | 162,502 |
| Russell Low PRESIDENT AND CEO, Director | May 15, 2026 | Tax withholding | −3,716 | $155.18 | $576.65K | 158,786 |
| Russell Low PRESIDENT AND CEO, Director | May 15, 2026 | Tax withholding | −1,722 | $155.18 | $267.22K | 157,064 |
| Russell Low PRESIDENT AND CEO, Director | May 15, 2026 | Tax withholding | −1,453 | $155.18 | $225.48K | 155,611 |
| Robert John Mahoney EVP Global Operations | May 15, 2026 | Tax withholding | −372 | $155.18 | $57.73K | 16,281 |
| Robert John Mahoney EVP Global Operations | May 15, 2026 | Award | +1,947 | – | – | 14,706 |
| Robert John Mahoney EVP Global Operations | May 15, 2026 | Tax withholding | −61 | $155.18 | $9.47K | 15,877 |
| Robert John Mahoney EVP Global Operations | May 15, 2026 | Tax withholding | −170 | $155.18 | $26.38K | 15,938 |
| Robert John Mahoney EVP Global Operations | May 15, 2026 | Tax withholding | −173 | $155.18 | $26.85K | 16,108 |
| Robert John Mahoney EVP Global Operations | May 15, 2026 | Award | +1,947 | – | – | 16,653 |
| Gregory B. Graves Director | May 15, 2026 | Award | +1,440 | – | – | 8,698 |
| Tzu Yin Chiu Director | May 15, 2026 | Award | +1,440 | – | – | 11,843 |
| Jorge Titinger Director | May 15, 2026 | Award | +1,440 | – | – | 5,917 |
Awards, option exercises, tax withholding and gifts are shown alongside open-market buys and sales. Each name links to the filing on SEC EDGAR.
Short interest
Shares sold short and not yet bought back, as of Oct 30, 2026 (FINRA, reported twice a month)
Short % of float
4.43%
1M shares short
Days to cover
4.1
At 0M shares a day
Change since last report
-7.0%
From 1M shares
Short volume, 20 days
65.8%
Of volume reported to FINRA
Shares sold short, last 12 months
Short sale volume counts trades marked short on any given day, including market-maker hedging, so it runs far higher than the share of Axcelis Technologies's stock actually held short. Settlement fails (shares not delivered on time) peaked at 36,116 shares on Oct 14, 2026 over the last 90 days.
Planned insider sales
Notices of proposed sale filed on Form 144 before shares are sold
| Seller | Filed | Shares | Market value | Planned sale | Acquired through |
|---|---|---|---|---|---|
| Necip Sayiner Director | Jun 3, 2026 | 1,586 | $249.70K | Jun 3, 2026 | Restricted stock vesting under a registered plan |
| Robert John Mahoney Officer | Jun 2, 2026 | 1,155 | $179.30K | Jun 2, 2026 | Restricted stock vesting under a registered plan |
| Todd Sutton Officer | May 27, 2026 | 2,000 | $319.98K | May 27, 2026 | Restricted stock vesting under a registered plan |
| Dennis Thomas St Director | May 22, 2026 | 900 | $139.83K | May 22, 2026 | Restricted stock vesting under a registered plan |
| Eileen Evans Officer | May 22, 2026 | 926 | $144.00K | May 22, 2026 | Restricted stock vesting under a registered plan |
| Gerald M. Blumenstock Officer | May 21, 2026 | 1,161 | $177.28K | May 21, 2026 | Restricted stock vesting under a registered plan |
| Christopher Tatnall Officer | May 20, 2026 | 1,166 | $174.61K | May 20, 2026 | Restricted stock vesting under a registered plan |
| Gregory B. Graves Director | May 19, 2026 | 3,225 | $456.70K | May 19, 2026 | Restricted stock vesting under a registered plan |
| Jeanne Quirk Director | May 19, 2026 | 1,789 | $250.85K | May 19, 2026 | Restricted stock vesting under a registered plan |
| John T. Kurtzweil Director | May 19, 2026 | 3,500 | $485.77K | May 19, 2026 | Restricted stock vesting under a registered plan |
| Todd Sutton Officer | May 14, 2026 | 2,574 | $421.75K | May 14, 2026 | Restricted stock vesting under a registered plan |
| Gerald M. Blumenstock Officer | May 14, 2026 | 1,015 | $164.75K | May 14, 2026 | Restricted stock vesting under a registered plan |
| Jorge Titinger Director | May 13, 2026 | 2,000 | $328.28K | May 13, 2026 | Restricted stock vesting under a registered plan |
| Gregory F Redinbo Officer | May 13, 2026 | 2,883 | $463.73K | May 13, 2026 | Restricted stock vesting under a registered plan |
| Robert John Mahoney Officer | May 12, 2026 | 2,258 | $363.54K | May 12, 2026 | Restricted stock vesting under a registered plan |
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