Axcelis Technologies, Inc.
Axcelis Technologies, Inc. (ACLS) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · ACLS · as of Mar 31, 2025
Ownership Breakdown
318
Institutional Holders
▼ 27 vs Q4
$1.54B
Total Inst. Value
▼ $618.74M vs Q4
30.73M
Shares Outstanding
freeFloat 98.57%
31.12M
13F Shares Held
▲ 198,347 vs Q4
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
ACLS largest shareholders · institutional ownership
Q1 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
BLACKROCK, INC. special industry machinery, nec | 5.34M | 16.55% | 16.55% | $265.16B | May 2, 2025 | ▼ 108.8K |
VANGUARD GROUP INC special industry machinery, nec | 4.44M | 13.76% | 13.76% | $220.53B | May 9, 2025 | ▲ 43.8K |
REINHART PARTNERS, INC. special industry machinery, nec | 1.44M | 4.47% | 4.47% | $71.58B | Apr 11, 2025 | ▲ 404.9K |
STATE STREET CORP special industry machinery, nec | 1.25M | 3.87% | 3.87% | $62.00B | May 15, 2025 | ▼ 53.0K |
AMERICAN CENTURY COMPANIES INC special industry machinery, nec | 1.14M | 3.54% | 3.54% | $56.65B | May 13, 2025 | ▲ 80.4K |
BNP PARIBAS ASSET MANAGEMENT HOLDING S.A. special industry machinery, nec | 1.02M | 3.16% | 3.16% | $50.70B | May 14, 2025 | ▲ 424.6K |
GEODE CAPITAL MANAGEMENT, LLC special industry machinery, nec | 925.6K | 2.87% | 2.87% | $45.98B | May 13, 2025 | ▲ 27.8K |
BANK OF AMERICA CORP /DE/ special industry machinery, nec | 919.4K | 2.85% | 2.85% | $45.67B | May 15, 2025 | ▲ 634.1K |
PRIMECAP MANAGEMENT CO/CA/ special industry machinery, nec | 835.1K | 2.59% | 2.59% | $41.48B | May 9, 2025 | ▼ 81.4K |
BOSTON TRUST WALDEN CORP special industry machinery, nec | 826.3K | 2.56% | 2.56% | $41.04B | Apr 21, 2025 | ▲ 6.2K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q1 2025 vs prior quarter
Q1 2025
36
Increased
+3.06M shares1
New Positions
first time holders13
Decreased
−1.39M shares0
Sold Out
fully exitedNet shares change (top 50)
+1.68M
+3.06M / −1.39M
Net new holders
+24
1 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
ACLS insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
21
Buy transactions
45
Sell transactions
0.47
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Sayiner Necip director | Jun 3, 2026 | Sale | 1,586 | $157.44 | $249.7K | 7.1K | Form 4 ↗ |
Sutton Todd VP Corporate Controller | May 27, 2026 | Sale | 2,000 | $159.99 | $320.0K | 6.4K | Form 4 ↗ |
St Dennis Thomas director | May 22, 2026 | Sale | 900 | $155.37 | $139.8K | 17.7K | Form 4 ↗ |
Evans Eileen EVP, General Counsel and Sec'y | May 22, 2026 | Sale | 926 | $155.51 | $144.0K | 31.3K | Form 4 ↗ |
Blumenstock Gerald M EVP, Research, Dev. & Eng. | May 21, 2026 | Sale | 1,161 | $152.70 | $177.3K | 20.5K | Form 4 ↗ |
Tatnall Christopher EVP Global Customer Operations | May 20, 2026 | Sale | 1,166 | $149.75 | $174.6K | 27.6K | Form 4 ↗ |
GRAVES GREGORY B director | May 19, 2026 | Sale | 2,625 | $141.41 | $371.2K | 6.1K | Form 4 ↗ |
GRAVES GREGORY B director | May 19, 2026 | Sale | 600 | $142.51 | $85.5K | 5.5K | Form 4 ↗ |
KURTZWEIL JOHN T director | May 19, 2026 | Sale | 3,500 | $138.79 | $485.8K | 33.0K | Form 4 ↗ |
Quirk Jeanne director | May 19, 2026 | Sale | 1,789 | $140.22 | $250.9K | 11.4K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Axcelis Technologies, Inc. (ACLS) is primarily owned by institutional investors, who hold approximately 100.0% of total shares outstanding. Company insiders own approximately 1.43%, while retail and public investors account for the remaining 0.00%.
The largest institutional shareholder of Axcelis Technologies, Inc. is BLACKROCK, INC., holding approximately 5.34 million shares — equal to 16.55% of outstanding shares — as of March 31, 2025.
A total of 318 institutional investors currently hold ACLS stock, with a combined institutional value of approximately $1.54 billion as of the most recent 13F filing period.
Frequently asked questions
ACLS ownershipAxcelis Technologies, Inc. (ACLS) is primarily owned by institutional investors, who hold approximately 100.0% of shares. The largest shareholder is BLACKROCK, INC. with a 16.55% stake. Company insiders hold 1.43%. Data sourced from SEC Form 13F as of March 31, 2025.