Who owns MKSI (MKSI)
Which tracked institutional funds hold MKSI, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See MKSI company fundamentals →
Ownership as of the 2026-Q1 13F filings. 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
The tracked-fund tape on MKSI is one-sided between 2025-Q4 and 2026-Q1: 285 added or opened and 80 trimmed or exited — on balance accumulating.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
MKSI’s largest tracked holder by dollar value, BlackRock, Inc., sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.1% of theirs — a 0.0pp gap the other way — the median holder sizes MKSI more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in MKSI divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2025-Q4 and 2026-Q1, across 615 tracked filers holding MKSI, 359 increased or opened the position and 256 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in MKSI between the 2025-Q4 and 2026-Q1 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 77
- VANGUARD PORTFOLIO MANAGEMENT LLC$847M
- VANGUARD CAPITAL MANAGEMENT LLC$693M
- Aspex Management (HK) Ltd$354M
- Whale Rock Capital Management LLC$300M
- Capital World Investors$294M
- SAMLYN CAPITAL, LLC$114M
Full exits 27
- VANGUARD GROUP INC$1.2B
- Southpoint Capital Advisors LP$96M
- GLENVIEW CAPITAL MANAGEMENT, LLC$12M
- BANK OF NOVA SCOTIA$12M
- MIZUHO MARKETS AMERICAS LLC$9M
- PINNBROOK CAPITAL MANAGEMENT LP$9M
Largest adds
- BlackRock, Inc.$307M
- Point72 Asset Management, L.P.$270M
- Invesco Ltd.$225M
- JPMORGAN CHASE & CO$193M
- GEODE CAPITAL MANAGEMENT, LLC$153M
- STATE STREET CORP$150M
Largest trims
- Amundi$474M
- VICTORY CAPITAL MANAGEMENT INC$208M
- COOKE & BIELER LP$106M
- NORGES BANK$75M
- Channing Capital Management, LLC$75M
- FMR LLC$70M
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| BlackRock, Inc. trimmed | 5,604,620 | $1.3B | 8.3% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 3,685,493 | $847M | 5.5% | 2026-Q1 |
| Invesco Ltd. trimmed | 3,660,133 | $841M | 5.4% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 3,014,201 | $693M | 4.5% | 2026-Q1 |
| STATE STREET CORP added | 2,057,732 | $473M | 3.1% | 2026-Q1 |
| Capital International Investors trimmed | 1,968,770 | $452M | 2.9% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 2,096,342 | $441M | 2.9% | 2026-Q1 |
| FMR LLC trimmed | 1,917,338 | $441M | 2.8% | 2026-Q1 |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 1,827,247 | $420M | 2.7% | 2026-Q1 |
| PRICE T ROWE ASSOCIATES INC /MD/ trimmed | 1,700,148 | $391M | 2.5% | 2026-Q1 |
| Point72 Asset Management, L.P. added | 1,610,331 | $370M | 2.4% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 1,539,319 | $354M | 2.3% | 2026-Q1 |
| Aspex Management (HK) Ltd new | 1,538,789 | $354M | 2.3% | 2026-Q1 |
| NEUBERGER BERMAN GROUP LLC trimmed | 1,433,529 | $329M | 2.1% | 2026-Q1 |
| Whale Rock Capital Management LLC new | 1,306,724 | $300M | 1.9% | 2026-Q1 |
| Capital World Investors new | 1,277,200 | $294M | 1.9% | 2026-Q1 |
| WESTFIELD CAPITAL MANAGEMENT CO LP added | 1,046,763 | $241M | 1.6% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 947,032 | $218M | 1.4% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC added | 894,369 | $206M | 1.3% | 2026-Q1 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 878,758 | $202M | 1.3% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 866,647 | $199M | 1.3% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP trimmed | 835,345 | $192M | 1.2% | 2026-Q1 |
| Bank of New York Mellon Corp added | 832,150 | $191M | 1.2% | 2026-Q1 |
| PRINCIPAL FINANCIAL GROUP INC trimmed | 614,230 | $141M | 0.9% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 615,522 | $137M | 0.9% | 2026-Q1 |
| NORTHERN TRUST CORP added | 569,224 | $131M | 0.8% | 2026-Q1 |
| MORGAN STANLEY trimmed | 515,063 | $118M | 0.8% | 2026-Q1 |
| SAMLYN CAPITAL, LLC added | 496,685 | $114M | 0.7% | 2026-Q1 |
| FRANKLIN RESOURCES INC trimmed | 475,893 | $109M | 0.7% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ trimmed | 463,709 | $107M | 0.7% | 2026-Q1 |
| FengHe Fund Management Pte. Ltd. new | 456,329 | $105M | 0.7% | 2026-Q1 |
| UBS Group AG added | 432,130 | $99M | 0.6% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 417,114 | $96M | 0.6% | 2026-Q1 |
| BALYASNY ASSET MANAGEMENT L.P. trimmed | 407,395 | $94M | 0.6% | 2026-Q1 |
| ROYCE & ASSOCIATES LP trimmed | 403,670 | $93M | 0.6% | 2026-Q1 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE trimmed | 400,319 | $92M | 0.6% | 2026-Q1 |
| Nuveen, LLC added | 378,158 | $87M | 0.6% | 2026-Q1 |
| Blue Grotto Capital, LLC trimmed | 375,000 | $86M | 0.6% | 2026-Q1 |
| Contour Asset Management LLC new | 374,868 | $86M | 0.6% | 2026-Q1 |
| Madison Asset Management, LLC trimmed | 338,336 | $78M | 0.5% | 2026-Q1 |
| RAYMOND JAMES FINANCIAL INC added | 337,962 | $76M | 0.5% | 2026-Q1 |
| TREMBLANT CAPITAL GROUP new | 329,786 | $76M | 0.5% | 2026-Q1 |
| NORGES BANK trimmed | 904,502 | $72M | 0.5% | 2026-Q1 |
| NORDEA INVESTMENT MANAGEMENT AB trimmed | 326,308 | $71M | 0.5% | 2026-Q1 |
| TimesSquare Capital Management, LLC added | 288,165 | $66M | 0.4% | 2026-Q1 |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC trimmed | 282,206 | $65M | 0.4% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC trimmed | 280,965 | $65M | 0.4% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 278,687 | $64M | 0.4% | 2026-Q1 |
| NOMURA HOLDINGS INC trimmed | 269,356 | $62M | 0.4% | 2026-Q1 |
| Quantinno Capital Management LP added | 259,749 | $60M | 0.4% | 2026-Q1 |
| Amundi trimmed | 254,748 | $59M | 0.4% | 2026-Q1 |
| Defiance ETFs, LLC added | 250,616 | $58M | 0.4% | 2026-Q1 |
| Penserra Capital Management LLC added | 250,616 | $58M | 0.4% | 2026-Q1 |
| Park West Asset Management LLC trimmed | 249,240 | $57M | 0.4% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 245,626 | $56M | 0.4% | 2026-Q1 |
| VALUE HOLDINGS MANAGEMENT CO. LLC trimmed | 245,050 | $56M | 0.4% | 2026-Q1 |
| Harvey Partners, LLC trimmed | 243,396 | $56M | 0.4% | 2026-Q1 |
| JANE STREET GROUP, LLC trimmed | 243,253 | $56M | 0.4% | 2026-Q1 |
| WELLS FARGO & COMPANY/MN trimmed | 243,038 | $56M | 0.4% | 2026-Q1 |
| SYSTEMATIC FINANCIAL MANAGEMENT LP trimmed | 242,063 | $56M | 0.4% | 2026-Q1 |
| NATIXIS ADVISORS, LLC trimmed | 232,006 | $53M | 0.3% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. added | 319,921 | $51M | 0.3% | 2026-Q1 |
| JONES FINANCIAL COMPANIES LLLP added | 223,782 | $50M | 0.3% | 2026-Q1 |
| DENDUR CAPITAL LP new | 214,500 | $49M | 0.3% | 2026-Q1 |
| COOKE & BIELER LP trimmed | 210,048 | $48M | 0.3% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 203,920 | $47M | 0.3% | 2026-Q1 |
| Gotham Asset Management, LLC trimmed | 195,403 | $45M | 0.3% | 2026-Q1 |
| Handelsbanken Fonder AB added | 192,500 | $44M | 0.3% | 2026-Q1 |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. added | 186,005 | $43M | 0.3% | 2026-Q1 |
| RHUMBLINE ADVISERS added | 179,960 | $41M | 0.3% | 2026-Q1 |
| Mizuho Markets Cayman LP | 175,000 | $40M | 0.3% | 2026-Q1 |
| LPL Financial LLC added | 174,975 | $40M | 0.3% | 2026-Q1 |
| Ceredex Value Advisors LLC trimmed | 169,475 | $39M | 0.3% | 2026-Q1 |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC added | 166,066 | $38M | 0.2% | 2026-Q1 |
| SORA INVESTORS LLC added | 162,762 | $37M | 0.2% | 2026-Q1 |
| BARCLAYS PLC trimmed | 161,499 | $37M | 0.2% | 2026-Q1 |
| FRONTIER CAPITAL MANAGEMENT CO LLC trimmed | 161,250 | $37M | 0.2% | 2026-Q1 |
| SummitTX Capital, L.P. trimmed | 160,909 | $37M | 0.2% | 2026-Q1 |
| Retirement Systems of Alabama added | 158,446 | $36M | 0.2% | 2026-Q1 |
| ROYAL BANK OF CANADA trimmed | 153,003 | $35M | 0.2% | 2026-Q1 |
| Delta Global Management LP trimmed | 151,117 | $35M | 0.2% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS trimmed | 148,697 | $34M | 0.2% | 2026-Q1 |
| CRAMER ROSENTHAL MCGLYNN LLC trimmed | 148,385 | $34M | 0.2% | 2026-Q1 |
| Thrivent Financial for Lutherans added | 143,677 | $33M | 0.2% | 2026-Q1 |
| Polaris Capital Management, LLC trimmed | 134,700 | $31M | 0.2% | 2026-Q1 |
| DEUTSCHE BANK AG\ trimmed | 133,050 | $31M | 0.2% | 2026-Q1 |
| Swiss National Bank added | 132,900 | $31M | 0.2% | 2026-Q1 |
| California Public Employees Retirement System added | 123,288 | $28M | 0.2% | 2026-Q1 |
| LIGHT STREET CAPITAL MANAGEMENT, LLC added | 122,264 | $28M | 0.2% | 2026-Q1 |
| D. E. Shaw & Co., Inc. added | 120,173 | $28M | 0.2% | 2026-Q1 |
| NEEDHAM INVESTMENT MANAGEMENT LLC trimmed | 120,000 | $28M | 0.2% | 2026-Q1 |
| BESSEMER GROUP INC trimmed | 117,851 | $27M | 0.2% | 2026-Q1 |
| BANK OF MONTREAL /CAN/ trimmed | 117,132 | $27M | 0.2% | 2026-Q1 |
| Talos Eurisko Asset Management LP new | 114,011 | $26M | 0.2% | 2026-Q1 |
| SG Americas Securities, LLC added | 110,343 | $25M | 0.2% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 7,374,077 | $1.2B | 7.6% | 2025-Q4 stale |
| Southpoint Capital Advisors LP new | 600,000 | $96M | 0.6% | 2025-Q4 stale |
| Kodai Capital Management LP added | 708,021 | $57M | 0.4% | 2025-Q1 stale |
| Capital Research Global Investors | 387,153 | $48M | 0.3% | 2025-Q3 stale |
| Freestone Grove Partners LP added | 413,764 | $41M | 0.3% | 2025-Q2 stale |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.