BLACKROCK
Rank #1
16.1%
- Shares
- 4.94M
- Change
- +109.20K
- Change %
- +2.26%
- Filing
- Mar 31, 2026
Increased
Methodology published · Market data, model notes, and corrections process are public · Data policy · Corrections policy
NASDAQ · TECHNOLOGY · Holders
Axcelis Technologies Inc (ACLS) Institutional Ownership & Insider Trading History
Top ACLS institutional shareholders, filing changes, and Form 4 insider activity with filters for buys, sales, option exercises, gifts, and tax withholding.
Section freshness
Price Jun 15, 9:40 AM EDT · Statements Mar 30, 8:00 PM EDT
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Data freshness
Prices update fastest. Fundamentals, analyst data, and news update on their own schedules, so check these timestamps before comparing signals.
Price time means the latest available trade or regular-market close. Other times show when that section was checked or published.
PriceLive
Last traded •
Source: Market data provider
Fundamentalsevery 1 day
Provider checked •
Source: Market data provider
Analystevery 1 day
Provider checked •
Source: Market data provider
Newsevery 4 hr
Latest item •
Source: Market data provider
Ownership read
ACLS insider sentiment: Net selling.
BLACKROCK is the largest loaded institutional holder. 91 sale rows and 0 purchase rows are visible in the loaded Form 4 history. Use the filters below to separate real buying and selling from option exercises, gifts, awards, and tax withholding.
Insider flow
ACLS
Purchases—
Sales98.54K
Directional bars ignore awards, gifts, conversions, and tax withholding rows.
Top holder
4.94M
BLACKROCK
Insider stance
Net selling
$13.16M sold / — bought
Latest filing
Jun 3, 2026
Most recent holder or insider filing date
Rows loaded
240
120 holder / 120 insider
- Holder rows
- 120
- Market data source
- Latest filing
- Jun 3, 2026
- Most recent holder or insider filing date
- Increased / initiated
- 59
- 55 decreased in loaded rows
- Insider rows
- 120
- Market data source
Top 120 institutional holders
Axcelis Technologies Inc (ACLS) institutional ownership
Ranked by reported share count, with position changes and latest filing dates where ownership data supplies them.
VANGUARD GROUP INC
Rank #2
13.4%
- Shares
- 4.12M
- Change
- -63.17K
- Change %
- -1.51%
- Filing
- Dec 31, 2025
Decreased
VANGUARD PORTFOLIO MANAGEMENT LLC
Rank #3
8.09%
- Shares
- 2.49M
- Change
- +2.49M
- Change %
- —
- Filing
- Mar 31, 2026
Initiated
FMR LLC
Rank #4
7.91%
- Shares
- 2.43M
- Change
- +1.82M
- Change %
- +2.98%
- Filing
- Mar 31, 2026
Increased
REINHART PARTNERS
Rank #5
5.39%
- Shares
- 1.66M
- Change
- +67.85K
- Change %
- +4.27%
- Filing
- Mar 31, 2026
Increased
VANGUARD CAPITAL MANAGEMENT LLC
Rank #6
4.50%
- Shares
- 1.38M
- Change
- +1.38M
- Change %
- —
- Filing
- Mar 31, 2026
Initiated
BALYASNY ASSET MANAGEMENT L.P.
Rank #7
4.44%
- Shares
- 1.36M
- Change
- +1.12M
- Change %
- +4.60%
- Filing
- Mar 31, 2026
Increased
VICTORY CAPITAL MANAGEMENT INC
Rank #8
4.16%
- Shares
- 1.28M
- Change
- -528.40K
- Change %
- -29.23%
- Filing
- Mar 31, 2026
Decreased
STATE STREET CORP
Rank #9
3.87%
- Shares
- 1.19M
- Change
- +2.82K
- Change %
- +24.00%
- Filing
- Mar 31, 2026
Increased
BNP PARIBAS ASSET MANAGEMENT HOLDING S.A.
Rank #10
3.27%
- Shares
- 1.01M
- Change
- -85.07K
- Change %
- -7.80%
- Filing
- Mar 31, 2026
Decreased
AMERICAN CENTURY COMPANIES INC
Rank #11
3.10%
- Shares
- 951.91K
- Change
- -281.73K
- Change %
- -22.84%
- Filing
- Mar 31, 2026
Decreased
DIMENSIONAL FUND ADVISORS LP
Rank #12
2.74%
- Shares
- 844.10K
- Change
- +3.06K
- Change %
- +36.00%
- Filing
- Mar 31, 2026
Increased
GEODE CAPITAL MANAGEMENT
Rank #13
2.64%
- Shares
- 811.26K
- Change
- -106.48K
- Change %
- -11.60%
- Filing
- Mar 31, 2026
Decreased
PRIMECAP MANAGEMENT CO
Rank #14
2.14%
- Shares
- 658.65K
- Change
- -6.29K
- Change %
- -95.00%
- Filing
- Mar 31, 2026
Decreased
MORGAN STANLEY
Rank #15
1.89%
- Shares
- 581.64K
- Change
- +231.42K
- Change %
- +66.08%
- Filing
- Mar 31, 2026
Increased
D. E. SHAW & CO.
Rank #16
1.77%
- Shares
- 544.42K
- Change
- +74.14K
- Change %
- +15.76%
- Filing
- Mar 31, 2026
Increased
GOLDMAN SACHS GROUP INC
Rank #17
1.62%
- Shares
- 497.62K
- Change
- -132.19K
- Change %
- -20.99%
- Filing
- Mar 31, 2026
Decreased
MANUFACTURERS LIFE INSURANCE COMPANY
Rank #18
1.60%
- Shares
- 491.75K
- Change
- +477.70K
- Change %
- +34.02%
- Filing
- Mar 31, 2026
Increased
CHARLES SCHWAB INVESTMENT MANAGEMENT INC
Rank #19
1.45%
- Shares
- 445.77K
- Change
- +14.57K
- Change %
- +3.38%
- Filing
- Mar 31, 2026
Increased
LSV ASSET MANAGEMENT
Rank #20
1.40%
- Shares
- 429.50K
- Change
- —
- Change %
- 0.00%
- Filing
- Mar 31, 2026
Unchanged
| # | Institution | % held | Shares | Change | Change % | Filing date |
|---|---|---|---|---|---|---|
| 1 | 16.1% | 4.94M | +109.20K Increased | +2.26% | Mar 31, 2026 | |
| 2 | 13.4% | 4.12M | -63.17K Decreased | -1.51% | Dec 31, 2025 | |
| 3 | 8.09% | 2.49M | +2.49M Initiated | — | Mar 31, 2026 | |
| 4 | 7.91% | 2.43M | +1.82M Increased | +2.98% | Mar 31, 2026 | |
| 5 | REINHART PARTNERS | 5.39% | 1.66M | +67.85K Increased | +4.27% | Mar 31, 2026 |
| 6 | 4.50% | 1.38M | +1.38M Initiated | — | Mar 31, 2026 | |
| 7 | BALYASNY ASSET MANAGEMENT L.P. | 4.44% | 1.36M | +1.12M Increased | +4.60% | Mar 31, 2026 |
| 8 | VICTORY CAPITAL MANAGEMENT INC | 4.16% | 1.28M | -528.40K Decreased | -29.23% | Mar 31, 2026 |
| 9 | 3.87% | 1.19M | +2.82K Increased | +24.00% | Mar 31, 2026 | |
| 10 | BNP PARIBAS ASSET MANAGEMENT HOLDING S.A. | 3.27% | 1.01M | -85.07K Decreased | -7.80% | Mar 31, 2026 |
| 11 | AMERICAN CENTURY COMPANIES INC | 3.10% | 951.91K | -281.73K Decreased | -22.84% | Mar 31, 2026 |
| 12 | 2.74% | 844.10K | +3.06K Increased | +36.00% | Mar 31, 2026 | |
| 13 | 2.64% | 811.26K | -106.48K Decreased | -11.60% | Mar 31, 2026 | |
| 14 | PRIMECAP MANAGEMENT CO | 2.14% | 658.65K | -6.29K Decreased | -95.00% | Mar 31, 2026 |
| 15 | 1.89% | 581.64K | +231.42K Increased | +66.08% | Mar 31, 2026 | |
| 16 | 1.77% | 544.42K | +74.14K Increased | +15.76% | Mar 31, 2026 | |
| 17 | 1.62% | 497.62K | -132.19K Decreased | -20.99% | Mar 31, 2026 | |
| 18 | MANUFACTURERS LIFE INSURANCE COMPANY | 1.60% | 491.75K | +477.70K Increased | +34.02% | Mar 31, 2026 |
| 19 | 1.45% | 445.77K | +14.57K Increased | +3.38% | Mar 31, 2026 | |
| 20 | LSV ASSET MANAGEMENT | 1.40% | 429.50K | — Unchanged | 0.00% | Mar 31, 2026 |
Showing 20 of 120 matching institutional rows.Load more institutions
Recent insider transactions
Axcelis Technologies Inc (ACLS) Form 4 filings
Action codes are translated so open-market buys and sales are separate from awards, gifts, conversions, and tax withholding.
SAYINER, NECIP
Director
- Shares
- 1.59K
- % company
- <0.01%
- Price
- $157.44
- Value
- $249,703
Filed Jun 3, 2026
MAHONEY, ROBERT JOHN
EVP Global Operations
- Shares
- 1.16K
- % company
- <0.01%
- Price
- $155.24
- Value
- $179,302
Filed Jun 2, 2026
SUTTON, TODD
VP Corporate Controller
- Shares
- 2.00K
- % company
- <0.01%
- Price
- $159.99
- Value
- $319,980
Filed May 27, 2026
EVANS, EILEEN
EVP, General Counsel and Sec'y
- Shares
- 926
- % company
- <0.01%
- Price
- $155.51
- Value
- $143,998
Filed May 22, 2026
ST, DENNIS THOMAS
Director
- Shares
- 900
- % company
- <0.01%
- Price
- $155.37
- Value
- $139,833
Filed May 22, 2026
BLUMENSTOCK, GERALD M
EVP, Research, Dev. & Eng.
- Shares
- 1.16K
- % company
- <0.01%
- Price
- $152.70
- Value
- $177,285
Filed May 21, 2026
TATNALL, CHRISTOPHER
EVP Global Customer Operations
- Shares
- 1.17K
- % company
- <0.01%
- Price
- $149.75
- Value
- $174,609
Filed May 20, 2026
GRAVES, GREGORY B
Director
- Shares
- 600
- % company
- <0.01%
- Price
- $142.51
- Value
- $85,509
Filed May 19, 2026
QUIRK, JEANNE
Director
- Shares
- 1.79K
- % company
- <0.01%
- Price
- $140.22
- Value
- $250,854
Filed May 19, 2026
KURTZWEIL, JOHN T
Director
- Shares
- 3.50K
- % company
- 0.01%
- Price
- $138.79
- Value
- $485,771
Filed May 19, 2026
GRAVES, GREGORY B
Director
- Shares
- 2.63K
- % company
- <0.01%
- Price
- $141.41
- Value
- $371,188
Filed May 19, 2026
GRAVES, GREGORY B
Director
- Shares
- 2.63K
- % company
- <0.01%
- Price
- $141.41
- Value
- $371,188
Filed May 19, 2026
| # | Insider | % company | Action | Shares | Price | Value | Filing date |
|---|---|---|---|---|---|---|---|
| 1 | SAYINER, NECIP Director | <0.01% | Sale to issuer | 1.59K | $157.44 | $249,703 | Jun 3, 2026 |
| 2 | MAHONEY, ROBERT JOHN EVP Global Operations | <0.01% | Sale to issuer | 1.16K | $155.24 | $179,302 | Jun 2, 2026 |
| 3 | SUTTON, TODD VP Corporate Controller | <0.01% | Sale to issuer | 2.00K | $159.99 | $319,980 | May 27, 2026 |
| 4 | EVANS, EILEEN EVP, General Counsel and Sec'y | <0.01% | Sale to issuer | 926 | $155.51 | $143,998 | May 22, 2026 |
| 5 | ST, DENNIS THOMAS Director | <0.01% | Sale to issuer | 900 | $155.37 | $139,833 | May 22, 2026 |
| 6 | BLUMENSTOCK, GERALD M EVP, Research, Dev. & Eng. | <0.01% | Sale to issuer | 1.16K | $152.70 | $177,285 | May 21, 2026 |
| 7 | TATNALL, CHRISTOPHER EVP Global Customer Operations | <0.01% | Sale to issuer | 1.17K | $149.75 | $174,609 | May 20, 2026 |
| 8 | GRAVES, GREGORY B Director | <0.01% | Sale to issuer | 600 | $142.51 | $85,509 | May 19, 2026 |
| 9 | QUIRK, JEANNE Director | <0.01% | Sale to issuer | 1.79K | $140.22 | $250,854 | May 19, 2026 |
| 10 | KURTZWEIL, JOHN T Director | 0.01% | Sale to issuer | 3.50K | $138.79 | $485,771 | May 19, 2026 |
| 11 | GRAVES, GREGORY B Director | <0.01% | Sale to issuer | 2.63K | $141.41 | $371,188 | May 19, 2026 |
| 12 | GRAVES, GREGORY B Director | <0.01% | Sale to issuer | 2.63K | $141.41 | $371,188 | May 19, 2026 |
Showing 12 of 120 matching Form 4 rows. Percent of company uses current shares outstanding when available.Load more insiders
Frequently asked
Common questions.
Who are the largest ACLS shareholders?
BLACKROCK is the largest institutional holder in the loaded ACLS ownership dataset, with 4.94 million shares, or about 16.05% of shares outstanding. The table ranks additional institutions by reported share count.
What is institutional ownership of ACLS?
The current TECHi snapshot has 120 loaded institutional rows for Axcelis Technologies Inc. 59 rows are marked increased or initiated, while 55 rows are marked decreased, with the latest holder filing dated Mar 31, 2026.
Where can I see Axcelis Technologies Inc insider transactions?
The insider transaction table currently shows 120 loaded Form 4 rows for ACLS, with the latest insider filing dated Jun 3, 2026. It separates purchases, sales, option exercises, awards, gifts, and tax withholding so administrative transactions are not confused with open-market trades.
Are ACLS insiders buying or selling?
The loaded ACLS Form 4 rows currently read Net selling: 91 sale rows and 0 purchase rows. Awards, gifts, conversions, and tax withholding are shown separately because they do not carry the same signal as open-market buying or selling.
Who is the most active ACLS insider in the loaded filings?
LOW, RUSSELL is the most active insider by absolute share movement in the loaded ACLS rows, with 52,756 shares moving across the visible filing history. Review the action labels before treating that activity as buying or selling.