Who owns MRK (MRK)
Which tracked institutional funds hold MRK, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See MRK 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 MRK is one-sided between 2025-Q4 and 2026-Q1: 1477 added or opened and 376 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
MRK’s largest tracked holder by dollar value, BlackRock, Inc., sizes it at 0.5% of its own reported 13F book, while the median holder sizes it at 0.5% of theirs — a 0.0pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in MRK 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 3752 tracked filers holding MRK, 1752 increased or opened the position and 1778 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 MRK 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 104
- VANGUARD CAPITAL MANAGEMENT LLC$19.4B
- VANGUARD PORTFOLIO MANAGEMENT LLC$8.1B
- VANGUARD FIDUCIARY TRUST CO$1.7B
- Vanguard Global Advisers, LLC$672M
- VANGUARD ASSET MANAGEMENT, Ltd$602M
- SEB Asset Management AB$198M
Full exits 114
- VANGUARD GROUP INC$26.8B
- Pacer Advisors, Inc.$916M
- Skandinaviska Enskilda Banken AB (publ)$192M
- VIRGINIA RETIREMENT SYSTEMS ET Al$143M
- Railway Pension Investments Ltd$122M
- COMERICA BANK$98M
Largest adds
- BlackRock, Inc.$3.8B
- JPMORGAN CHASE & CO$3.2B
- STATE STREET CORP$1.7B
- FMR LLC$1.0B
- WELLINGTON MANAGEMENT GROUP LLP$1.0B
- MORGAN STANLEY$999M
Largest trims
- ARROWSTREET CAPITAL, LIMITED PARTNERSHIP$694M
- NORGES BANK$567M
- MILLENNIUM MANAGEMENT LLC$479M
- MASSACHUSETTS FINANCIAL SERVICES CO /MA/$429M
- UBS Group AG$343M
- LOS ANGELES CAPITAL MANAGEMENT LLC$316M
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. added | 223,515,009 | $26.9B | 12.1% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 160,987,624 | $19.4B | 8.7% | 2026-Q1 |
| STATE STREET CORP trimmed | 119,325,673 | $14.5B | 6.5% | 2026-Q1 |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 84,314,971 | $10.1B | 4.6% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 67,304,305 | $8.1B | 3.7% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC trimmed | 59,558,154 | $7.1B | 3.2% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 52,972,983 | $6.3B | 2.8% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 49,765,225 | $6.0B | 2.7% | 2026-Q1 |
| MORGAN STANLEY added | 47,632,487 | $5.7B | 2.6% | 2026-Q1 |
| FMR LLC added | 44,436,327 | $5.3B | 2.4% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 30,774,221 | $3.7B | 1.7% | 2026-Q1 |
| NORGES BANK added | 38,227,690 | $3.4B | 1.5% | 2026-Q1 |
| NORTHERN TRUST CORP trimmed | 27,090,023 | $3.3B | 1.5% | 2026-Q1 |
| Fisher Asset Management, LLC added | 26,436,284 | $3.2B | 1.4% | 2026-Q1 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 23,042,842 | $2.8B | 1.3% | 2026-Q1 |
| Invesco Ltd. added | 21,624,033 | $2.6B | 1.2% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 20,414,819 | $2.5B | 1.1% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 20,133,379 | $2.4B | 1.1% | 2026-Q1 |
| Legal & General Group Plc trimmed | 19,538,545 | $2.4B | 1.1% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 18,713,363 | $2.3B | 1.0% | 2026-Q1 |
| AMERIPRISE FINANCIAL INC added | 16,262,708 | $2.0B | 0.9% | 2026-Q1 |
| FRANKLIN RESOURCES INC added | 16,267,205 | $2.0B | 0.9% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 15,456,039 | $1.9B | 0.8% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 13,964,179 | $1.7B | 0.8% | 2026-Q1 |
| UBS Group AG trimmed | 13,933,630 | $1.7B | 0.8% | 2026-Q1 |
| STATE FARM MUTUAL AUTOMOBILE INSURANCE CO | 13,794,969 | $1.7B | 0.7% | 2026-Q1 |
| Amundi added | 13,764,954 | $1.7B | 0.7% | 2026-Q1 |
| ROYAL BANK OF CANADA added | 13,201,722 | $1.6B | 0.7% | 2026-Q1 |
| DEUTSCHE BANK AG\ trimmed | 12,540,774 | $1.5B | 0.7% | 2026-Q1 |
| HARRIS ASSOCIATES L P trimmed | 12,366,933 | $1.5B | 0.7% | 2026-Q1 |
| WELLS FARGO & COMPANY/MN added | 11,446,845 | $1.4B | 0.6% | 2026-Q1 |
| Nuveen, LLC added | 10,099,764 | $1.2B | 0.5% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. added | 11,301,486 | $1.2B | 0.5% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC trimmed | 8,625,846 | $1.0B | 0.5% | 2026-Q1 |
| NORDEA INVESTMENT MANAGEMENT AB trimmed | 8,527,993 | $1.0B | 0.5% | 2026-Q1 |
| STIFEL FINANCIAL CORP trimmed | 8,291,826 | $997M | 0.5% | 2026-Q1 |
| BARROW HANLEY MEWHINNEY & STRAUSS LLC added | 7,917,866 | $952M | 0.4% | 2026-Q1 |
| HSBC HOLDINGS PLC trimmed | 7,634,112 | $918M | 0.4% | 2026-Q1 |
| BARCLAYS PLC added | 7,557,518 | $909M | 0.4% | 2026-Q1 |
| PNC FINANCIAL SERVICES GROUP, INC. trimmed | 7,530,441 | $906M | 0.4% | 2026-Q1 |
| California Public Employees Retirement System trimmed | 7,383,088 | $888M | 0.4% | 2026-Q1 |
| Swiss National Bank added | 7,284,151 | $876M | 0.4% | 2026-Q1 |
| Swedbank AB trimmed | 7,091,711 | $853M | 0.4% | 2026-Q1 |
| Grantham, Mayo, Van Otterloo & Co. LLC added | 7,013,777 | $844M | 0.4% | 2026-Q1 |
| Aristotle Capital Management, LLC trimmed | 6,894,432 | $829M | 0.4% | 2026-Q1 |
| RAYMOND JAMES FINANCIAL INC trimmed | 6,585,514 | $792M | 0.4% | 2026-Q1 |
| Sumitomo Mitsui Trust Group, Inc. trimmed | 6,269,316 | $754M | 0.3% | 2026-Q1 |
| JENNISON ASSOCIATES LLC added | 6,249,337 | $752M | 0.3% | 2026-Q1 |
| Mitsubishi UFJ Asset Management Co., Ltd. added | 5,782,329 | $696M | 0.3% | 2026-Q1 |
| National Pension Service trimmed | 5,762,086 | $693M | 0.3% | 2026-Q1 |
| Vanguard Global Advisers, LLC new | 5,585,694 | $672M | 0.3% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC added | 5,547,858 | $667M | 0.3% | 2026-Q1 |
| DekaBank Deutsche Girozentrale | 5,427,912 | $652M | 0.3% | 2026-Q1 |
| VOYA INVESTMENT MANAGEMENT LLC added | 5,159,124 | $621M | 0.3% | 2026-Q1 |
| LSV ASSET MANAGEMENT trimmed | 5,088,709 | $612M | 0.3% | 2026-Q1 |
| VANGUARD ASSET MANAGEMENT, Ltd new | 5,003,623 | $602M | 0.3% | 2026-Q1 |
| BANK OF MONTREAL /CAN/ trimmed | 4,831,161 | $581M | 0.3% | 2026-Q1 |
| PRINCIPAL FINANCIAL GROUP INC trimmed | 4,709,942 | $567M | 0.3% | 2026-Q1 |
| Aberdeen Group plc added | 4,665,193 | $561M | 0.3% | 2026-Q1 |
| Capital Wealth Planning, LLC trimmed | 4,516,730 | $543M | 0.2% | 2026-Q1 |
| FIRST TRUST ADVISORS LP trimmed | 4,465,569 | $537M | 0.2% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC added | 4,202,381 | $505M | 0.2% | 2026-Q1 |
| Allianz Asset Management GmbH trimmed | 3,964,890 | $477M | 0.2% | 2026-Q1 |
| ENVESTNET ASSET MANAGEMENT INC added | 3,852,976 | $463M | 0.2% | 2026-Q1 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM trimmed | 3,835,612 | $461M | 0.2% | 2026-Q1 |
| CITADEL ADVISORS LLC trimmed | 3,821,227 | $460M | 0.2% | 2026-Q1 |
| Caisse de depot et placement du Quebec trimmed | 3,799,379 | $457M | 0.2% | 2026-Q1 |
| RHUMBLINE ADVISERS trimmed | 3,797,430 | $457M | 0.2% | 2026-Q1 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 3,789,757 | $456M | 0.2% | 2026-Q1 |
| LPL Financial LLC added | 3,782,188 | $455M | 0.2% | 2026-Q1 |
| THORNBURG INVESTMENT MANAGEMENT INC | 3,728,673 | $449M | 0.2% | 2026-Q1 |
| Bank Julius Baer & Co. Ltd, Zurich added | 3,700,222 | $443M | 0.2% | 2026-Q1 |
| HighTower Advisors, LLC trimmed | 3,635,404 | $437M | 0.2% | 2026-Q1 |
| CANADA PENSION PLAN INVESTMENT BOARD trimmed | 3,616,870 | $435M | 0.2% | 2026-Q1 |
| NEW YORK STATE COMMON RETIREMENT FUND trimmed | 3,516,025 | $423M | 0.2% | 2026-Q1 |
| D. E. Shaw & Co., Inc. trimmed | 3,397,582 | $409M | 0.2% | 2026-Q1 |
| NEUBERGER BERMAN GROUP LLC added | 3,280,851 | $395M | 0.2% | 2026-Q1 |
| LAZARD ASSET MANAGEMENT LLC trimmed | 3,254,331 | $391M | 0.2% | 2026-Q1 |
| AVIVA PLC added | 3,236,573 | $389M | 0.2% | 2026-Q1 |
| Beutel, Goodman & Co Ltd. trimmed | 3,029,891 | $364M | 0.2% | 2026-Q1 |
| FEDERATED HERMES, INC. added | 3,008,096 | $362M | 0.2% | 2026-Q1 |
| CANADA LIFE ASSURANCE Co added | 2,974,102 | $359M | 0.2% | 2026-Q1 |
| NATIXIS ADVISORS, LLC added | 2,970,290 | $357M | 0.2% | 2026-Q1 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 2,936,330 | $353M | 0.2% | 2026-Q1 |
| ROYAL LONDON ASSET MANAGEMENT LTD trimmed | 2,896,154 | $348M | 0.2% | 2026-Q1 |
| JANUS HENDERSON GROUP PLC added | 2,880,199 | $346M | 0.2% | 2026-Q1 |
| Eurizon Capital SGR S.p.A. added | 2,822,423 | $339M | 0.2% | 2026-Q1 |
| Mariner, LLC added | 2,795,221 | $336M | 0.2% | 2026-Q1 |
| CITIGROUP INC added | 2,779,106 | $334M | 0.2% | 2026-Q1 |
| MARSHALL WACE, LLP trimmed | 2,778,301 | $334M | 0.2% | 2026-Q1 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. trimmed | 2,687,439 | $323M | 0.1% | 2026-Q1 |
| JONES FINANCIAL COMPANIES LLLP added | 2,659,381 | $318M | 0.1% | 2026-Q1 |
| Ensign Peak Advisors, Inc added | 2,613,009 | $314M | 0.1% | 2026-Q1 |
| MACKENZIE FINANCIAL CORP added | 2,517,435 | $303M | 0.1% | 2026-Q1 |
| Russell Investments Group, Ltd. trimmed | 2,526,631 | $302M | 0.1% | 2026-Q1 |
| Smead Capital Management, Inc. trimmed | 2,471,398 | $297M | 0.1% | 2026-Q1 |
| Corient Private Wealth LLC trimmed | 2,428,276 | $291M | 0.1% | 2026-Q1 |
| Thrivent Financial for Lutherans trimmed | 2,351,669 | $283M | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC added | 254,307,697 | $26.8B | 12.1% | 2025-Q4 stale |
| Pacer Advisors, Inc. trimmed | 4,351,397 | $458M | 0.2% | 2025-Q4 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.