Who owns Mirum Pharmaceuticals (MIRM)
Which tracked institutional funds hold MIRM, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See MIRM company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 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 MIRM is one-sided between 2026-Q1 and 2026-Q2: 158 added or opened and 48 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
MIRM’s largest tracked holder by dollar value, Frazier Life Sciences Management, L.P., sizes it at 19.6% of its own reported 13F book, while the median holder sizes it at 0.1% of theirs — a 19.5pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in MIRM 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 2026-Q1 and 2026-Q2, across 313 tracked filers holding MIRM, 178 increased or opened the position and 149 reduced or closed it; over the same quarter, open-market insider Form 4s were net sales.
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 MIRM between the 2026-Q1 and 2026-Q2 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 22
- Jupiter Topco LLC$692M
- PERCEPTIVE ADVISORS LLC$14M
- Seven Fleet Capital Management LP$13M
- Capricorn Fund Managers Ltd$12M
- PEREGRINE CAPITAL MANAGEMENT LLC$10M
- ARISTEIA CAPITAL, L.L.C.$8M
Full exits 24
- JANUS HENDERSON GROUP PLC$627M
- CITADEL ADVISORS LLC$97M
- Paradigm Biocapital Advisors LP$58M
- LORD, ABBETT & CO. LLC$57M
- Point72 Asset Management, L.P.$32M
- Logos Global Management LP$18M
Largest adds
- BlackRock, Inc.$339M
- FMR LLC$250M
- Frazier Life Sciences Management, L.P.$190M
- PRICE T ROWE ASSOCIATES INC /MD/$152M
- VANGUARD PORTFOLIO MANAGEMENT LLC$146M
- Invesco Ltd.$139M
Largest trims
- Soleus Capital Management, L.P.$28M
- MILLENNIUM MANAGEMENT LLC$23M
- BVF INC/IL$23M
- BNP PARIBAS FINANCIAL MARKETS$13M
- D. E. Shaw & Co., Inc.$12M
- First Turn Management, LLC$11M
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| Frazier Life Sciences Management, L.P. | 7,679,684 | $899M | 11.3% | 2026-Q2 |
| Jupiter Topco LLC new | 5,909,184 | $692M | 8.7% | 2026-Q2 |
| BlackRock, Inc. added | 4,390,063 | $514M | 6.4% | 2026-Q2 |
| FMR LLC added | 3,670,314 | $430M | 5.4% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 2,655,607 | $311M | 3.9% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC added | 2,377,019 | $278M | 3.5% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC trimmed | 2,254,109 | $264M | 3.3% | 2026-Q2 |
| STATE STREET CORP added | 2,170,689 | $254M | 3.2% | 2026-Q2 |
| WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC added | 1,404,741 | $164M | 2.1% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 1,393,908 | $163M | 2.0% | 2026-Q2 |
| Invesco Ltd. added | 1,364,084 | $160M | 2.0% | 2026-Q2 |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 1,309,987 | $153M | 1.9% | 2026-Q2 |
| EVENTIDE ASSET MANAGEMENT, LLC trimmed | 1,248,389 | $146M | 1.8% | 2026-Q2 |
| TANG CAPITAL MANAGEMENT LLC | 1,236,027 | $145M | 1.8% | 2026-Q2 |
| Capital World Investors added | 1,153,480 | $135M | 1.7% | 2026-Q2 |
| FRANKLIN RESOURCES INC added | 1,152,770 | $135M | 1.7% | 2026-Q2 |
| NOVO HOLDINGS A/S trimmed | 1,125,000 | $132M | 1.6% | 2026-Q2 |
| TCG Crossover Management, LLC | 1,062,049 | $124M | 1.6% | 2026-Q2 |
| BVF INC/IL trimmed | 1,056,027 | $124M | 1.5% | 2026-Q2 |
| Polar Capital Holdings Plc added | 845,524 | $99M | 1.2% | 2026-Q2 |
| Rock Springs Capital Management LP trimmed | 798,145 | $93M | 1.2% | 2026-Q2 |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. added | 752,044 | $88M | 1.1% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC added | 726,694 | $85M | 1.1% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP trimmed | 690,318 | $81M | 1.0% | 2026-Q2 |
| Bank of New York Mellon Corp added | 669,974 | $78M | 1.0% | 2026-Q2 |
| Clearbridge Investments, LLC trimmed | 639,734 | $75M | 0.9% | 2026-Q2 |
| BNP PARIBAS FINANCIAL MARKETS trimmed | 606,427 | $71M | 0.9% | 2026-Q2 |
| Woodline Partners LP | 567,894 | $66M | 0.8% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ trimmed | 561,724 | $66M | 0.8% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC trimmed | 549,874 | $64M | 0.8% | 2026-Q2 |
| Pictet Asset Management Holding SA added | 526,443 | $62M | 0.8% | 2026-Q2 |
| BALYASNY ASSET MANAGEMENT L.P. trimmed | 489,170 | $57M | 0.7% | 2026-Q2 |
| EMERALD ADVISERS, LLC added | 468,295 | $55M | 0.7% | 2026-Q2 |
| NORTHERN TRUST CORP added | 452,036 | $53M | 0.7% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 449,429 | $53M | 0.7% | 2026-Q2 |
| BAKER BROS. ADVISORS LP | 445,975 | $52M | 0.7% | 2026-Q2 |
| LOOMIS SAYLES & CO L P trimmed | 443,636 | $52M | 0.7% | 2026-Q2 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 442,185 | $52M | 0.6% | 2026-Q2 |
| FEDERATED HERMES, INC. trimmed | 436,635 | $51M | 0.6% | 2026-Q2 |
| NEXT CENTURY GROWTH INVESTORS LLC added | 420,213 | $49M | 0.6% | 2026-Q2 |
| Connor, Clark & Lunn Investment Management Ltd. trimmed | 420,063 | $49M | 0.6% | 2026-Q2 |
| BOONE CAPITAL MANAGEMENT LLC trimmed | 415,641 | $49M | 0.6% | 2026-Q2 |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ added | 384,570 | $45M | 0.6% | 2026-Q2 |
| UBS Group AG trimmed | 379,760 | $44M | 0.6% | 2026-Q2 |
| Candriam S.C.A. trimmed | 376,143 | $44M | 0.6% | 2026-Q2 |
| TimesSquare Capital Management, LLC trimmed | 367,281 | $43M | 0.5% | 2026-Q2 |
| MORGAN STANLEY trimmed | 351,404 | $41M | 0.5% | 2026-Q2 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. trimmed | 350,000 | $41M | 0.5% | 2026-Q2 |
| Palo Alto Investors LP added | 348,808 | $41M | 0.5% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 348,230 | $41M | 0.5% | 2026-Q2 |
| Octagon Capital Advisors LP | 338,900 | $40M | 0.5% | 2026-Q2 |
| PANAGORA ASSET MANAGEMENT INC added | 337,461 | $40M | 0.5% | 2026-Q2 |
| Nuveen, LLC trimmed | 329,282 | $39M | 0.5% | 2026-Q2 |
| RA CAPITAL MANAGEMENT, L.P. | 318,554 | $37M | 0.5% | 2026-Q2 |
| Hood River Capital Management LLC added | 306,439 | $36M | 0.4% | 2026-Q2 |
| Penn Capital Management Company, LLC added | 298,914 | $35M | 0.4% | 2026-Q2 |
| EMERALD MUTUAL FUND ADVISERS TRUST added | 289,372 | $34M | 0.4% | 2026-Q2 |
| Patient Square Capital LP added | 260,500 | $30M | 0.4% | 2026-Q2 |
| NEW YORK STATE COMMON RETIREMENT FUND added | 250,558 | $29M | 0.4% | 2026-Q2 |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. trimmed | 248,963 | $29M | 0.4% | 2026-Q2 |
| RAYMOND JAMES FINANCIAL INC added | 233,311 | $27M | 0.3% | 2026-Q2 |
| NAN FUNG TRINITY (HK) LTD | 232,679 | $27M | 0.3% | 2026-Q2 |
| Trails Edge Capital Partners, LP trimmed | 223,312 | $26M | 0.3% | 2026-Q2 |
| Russell Investments Group, Ltd. added | 219,462 | $26M | 0.3% | 2026-Q2 |
| First Turn Management, LLC trimmed | 218,051 | $26M | 0.3% | 2026-Q2 |
| Erste Asset Management GmbH trimmed | 205,000 | $25M | 0.3% | 2026-Q2 |
| SEGALL BRYANT & HAMILL, LLC added | 178,980 | $21M | 0.3% | 2026-Q2 |
| Ensign Peak Advisors, Inc trimmed | 175,598 | $21M | 0.3% | 2026-Q2 |
| Nicholas Investment Partners, LP added | 172,695 | $20M | 0.3% | 2026-Q2 |
| CITIGROUP INC added | 165,136 | $19M | 0.2% | 2026-Q2 |
| Legal & General Group Plc added | 159,231 | $19M | 0.2% | 2026-Q2 |
| NEUBERGER BERMAN GROUP LLC added | 139,447 | $16M | 0.2% | 2026-Q2 |
| Rhenman & Partners Asset Management AB added | 139,205 | $16M | 0.2% | 2026-Q2 |
| FIRST TRUST ADVISORS LP trimmed | 136,141 | $16M | 0.2% | 2026-Q2 |
| Highlander Partners, L.P. | 122,980 | $14M | 0.2% | 2026-Q2 |
| PDT Partners, LLC trimmed | 122,041 | $14M | 0.2% | 2026-Q2 |
| PERCEPTIVE ADVISORS LLC trimmed | 115,391 | $14M | 0.2% | 2026-Q2 |
| RICE HALL JAMES & ASSOCIATES, LLC trimmed | 110,673 | $13M | 0.2% | 2026-Q2 |
| Seven Fleet Capital Management LP new | 110,393 | $13M | 0.2% | 2026-Q2 |
| ESSEX INVESTMENT MANAGEMENT CO LLC trimmed | 105,669 | $12M | 0.2% | 2026-Q2 |
| PRINCIPAL FINANCIAL GROUP INC added | 101,900 | $12M | 0.1% | 2026-Q2 |
| Capricorn Fund Managers Ltd new | 101,240 | $12M | 0.1% | 2026-Q2 |
| Atle Fund Management AB trimmed | 100,807 | $12M | 0.1% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC trimmed | 96,213 | $11M | 0.1% | 2026-Q2 |
| PEREGRINE CAPITAL MANAGEMENT LLC new | 88,820 | $10M | 0.1% | 2026-Q2 |
| VOYA INVESTMENT MANAGEMENT LLC added | 86,257 | $10M | 0.1% | 2026-Q2 |
| Swiss National Bank added | 84,800 | $10M | 0.1% | 2026-Q2 |
| Voleon Capital Management LP trimmed | 82,877 | $10M | 0.1% | 2026-Q2 |
| Fisher Asset Management, LLC trimmed | 82,476 | $10M | 0.1% | 2026-Q2 |
| DEUTSCHE BANK AG\ added | 81,586 | $10M | 0.1% | 2026-Q2 |
| JPMORGAN CHASE & CO trimmed | 81,001 | $10M | 0.1% | 2026-Q2 |
| SILVERCREST ASSET MANAGEMENT GROUP LLC trimmed | 77,278 | $9M | 0.1% | 2026-Q2 |
| Soleus Capital Management, L.P. trimmed | 75,000 | $9M | 0.1% | 2026-Q2 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE added | 74,750 | $9M | 0.1% | 2026-Q2 |
| Alyeska Investment Group, L.P. added | 73,959 | $9M | 0.1% | 2026-Q2 |
| SEI INVESTMENTS CO trimmed | 71,412 | $8M | 0.1% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 68,725 | $8M | 0.1% | 2026-Q2 |
| ARISTEIA CAPITAL, L.L.C. new | 64,475 | $8M | 0.1% | 2026-Q2 |
| Lisanti Capital Growth, LLC added | 63,295 | $7M | 0.1% | 2026-Q2 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 60,861 | $7M | 0.1% | 2026-Q2 |
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.