MIRUM PHARMACEUTICALS INC MIRM
COM · Common Stock · CUSIP 604749101 · ISIN US6047491013
Biopharmaceutical company
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersFoster City, CA
- Founded2018
- Websitemirumpharma.com
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($9.1m this quarter). Holder counts are more reliable. Shares outstanding: 50.2m as of 2025-08-01, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $50.89. Options: 6 managers hold calls ($1.5m notional), 4 hold puts ($5.1m).
Trends to Q2 2025
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 112 |
| Q4 2022 | 105 |
| Q1 2023 | 119 |
| Q2 2023 | 148 |
| Q3 2023 | 161 |
| Q4 2023 | 189 |
| Q1 2024 | 174 |
| Q2 2024 | 163 |
| Q3 2024 | 180 |
| Q4 2024 | 207 |
| Q1 2025 | 216 |
| Q2 2025 | 216 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2023 | 99 | 48 |
| Q4 2023 | 105 | 67 |
| Q1 2024 | 91 | 89 |
| Q2 2024 | 88 | 83 |
| Q3 2024 | 108 | 60 |
| Q4 2024 | 105 | 76 |
| Q1 2025 | 117 | 87 |
| Q2 2025 | 111 | 112 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2024 | $8.0m | $6.9m | 0.86 |
| Q4 2024 | $653.0k | $4.1m | 6.31 |
| Q1 2025 | $2.4m | $4.8m | 1.97 |
| Q2 2025 | $1.5m | $5.1m | 3.27 |
Biggest buyers
| JANUS HENDERSON GROUP PLC | Added | +470.2k |
| EMERALD ADVISERS, LLC | New | +305.8k |
| Soleus Capital Management, L.P. | New | +298.7k |
| Bank of New York Mellon Corp | Added | +249.3k |
| BlackRock, Inc. | Added | +237.5k |
| Eversept Partners, LP | New | +232.2k |
| EMERALD MUTUAL FUND ADVISERS TRUST | New | +217.5k |
| RENAISSANCE TECHNOLOGIES LLC | Added | +207.8k |
| JPMORGAN CHASE & CO | Added | +192.3k |
| WELLS FARGO & COMPANY/MN | Added | +164.5k |
Biggest sellers
| Invesco Ltd. | Reduced | -248.8k |
| Polar Capital Holdings Plc | Reduced | -200.0k |
| MILLENNIUM MANAGEMENT LLC | Reduced | -191.1k |
| JANE STREET GROUP, LLC | Reduced | -159.3k |
| Cubist Systematic Strategies, LLC | Reduced | -151.9k |
| Nan Fung Group Holdings Ltd | Sold out | -146.8k |
| Prosight Management, LP | Reduced | -143.3k |
| Rock Springs Capital Management LP | Reduced | -133.6k |
| STATE STREET CORP | Reduced | -118.9k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Reduced | -102.0k |
Biggest calls
| NOMURA HOLDINGS INC | Unchanged | $641.2k12.6k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | New | $346.1k6.8k shares |
| CITADEL ADVISORS LLC | Reduced | $300.3k5.9k shares |
| SIMPLEX TRADING, LLC | Reduced | $147.0k2.9k shares |
| GROUP ONE TRADING LLC | Reduced | $112.0k2.2k shares |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | Unchanged | $00 shares |
Biggest puts
| JANE STREET GROUP, LLC | Added | $4.0m78.0k shares |
| CITADEL ADVISORS LLC | Reduced | $1.1m20.9k shares |
| GROUP ONE TRADING LLC | Reduced | $25.4k500 shares |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | Unchanged | $00 shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| Janus Henderson Group Ltd. 13G · institution -2.1 pts · filed 2026-08-13 | 9.7% |
Frazier Life Sciences IX, L.P.
13D · may seek influence
-0.8 pts · filed 2026-01-27
Stated purposeItem 4 is hereby amended and restated in its entirety to read as follows: Each of FLS IX, FLS X, FLSPF, FLS XI and FLS XII acquired the FLS IX Shares, the FLS X Shares, the FLSPF Shares, the FLS XI Shares and the FLS XII Shares, as the case may be, for investment purposes. Depending on market conditions, its continuing evaluation of the business and prospects of the Issuer and other factors, FLS IX, FLS X, FLSPF, FLS XI and FLS XII and the other Reporting Persons may dispose of or acquire additional shares of the Issuer. Except as set forth above, none of the Reporting Persons has any present plans which relate to or would result in: (a) The acquisition by any person of additional securities of the Issuer, or the disposition of securities of the Issuer; (b) An extraordinary corporat… Full filing |
6.8% |
| FMR LLC 13G · institution new · filed 2026-08-06 | 6.2% |
| BlackRock, Inc. 13G · institution filed 2026-04-27 | 5.7% |
Fell to 5% or below in the last year: VANGUARD GROUP INC (0.0%, 2026-03-27), EVENTIDE ASSET MANAGEMENT, LLC (4.1%, 2026-02-13), BIOTECHNOLOGY VALUE FUND L P (3.0%, 2025-11-14)
Insider purchases and sales in Q2 2025
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q3 2023 | 2 | $4.5m | 6 | $785.0k | — |
| Q4 2023 | 1 | $82.4k | 1 | $81.0k | — |
| Q1 2024 | 1 | $101.2k | 5 | $617.5k | — |
| Q2 2024 | 0 | — | 2 | $1.2m | $1.2m |
| Q3 2024 | 1 | $13.9k | 1 | $12.8k | — |
| Q4 2024 | 0 | — | 1 | $117.8k | — |
| Q1 2025 | 1 | $280.1k | 4 | $8.7m | $4.5m |
| Q2 2025 | 0 | — | 2 | $532.9k | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2025-06-11 | Fairey William Director | Sold | $155.1k3.2k shares |
| 2025-06-03 | Ramasastry Saira Director | Sold | $114.3k2.5k shares |
| 2025-06-02 | Ramasastry Saira Director | Sold | $263.5k5.7k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2025
| Manager | Shares | Change |
|---|---|---|
| Frazier Life Sciences Management, L.P. 13.83% of their portfolio | 6.8m $345.8m | Unchanged |
| JANUS HENDERSON GROUP PLC 0.13% of their portfolio | 5.2m $266.5m | Added +470.2k |
| BlackRock, Inc. 0.00% of their portfolio | 3.6m $182.0m | Added +237.5k |
| BVF INC/IL 5.02% of their portfolio | 2.8m $140.5m | Reduced -35.2k |
| EVENTIDE ASSET MANAGEMENT, LLC 2.35% of their portfolio | 2.6m $134.2m | Added +110.5k |
| VANGUARD GROUP INC 0.00% of their portfolio | 2.6m $130.5m | Added +24.8k |
| NOVO HOLDINGS A/S 5.39% of their portfolio | 1.5m $76.3m | Added +55 |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.01% of their portfolio | 1.4m $72.1m | Added +2.1k |
| CITADEL ADVISORS LLC 0.06% of their portfolio | 1.4m $71.6m | Reduced -39.6k |
| STATE STREET CORP 0.00% of their portfolio | 1.4m $70.0m | Reduced -118.9k |
| TANG CAPITAL MANAGEMENT LLC 3.18% of their portfolio | 1.2m $62.9m | Reduced -1.1k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 1.0m $52.4m | Added +66.0k |
| Clearbridge Investments, LLC 0.04% of their portfolio | 1.0m $52.3m | Added +49.5k |
| Polar Capital Holdings Plc 0.26% of their portfolio | 975.0k $49.6m | Reduced -200.0k |
| Rock Springs Capital Management LP 2.59% of their portfolio | 818.2k $41.6m | Reduced -133.6k |
| LORD, ABBETT & CO. LLC 0.13% of their portfolio | 771.1k $39.2m | Reduced -42.3k |
| Pictet Asset Management Holding SA 0.04% of their portfolio | 701.2k $35.7m | Reduced -77.1k |
| BOONE CAPITAL MANAGEMENT LLC 14.00% of their portfolio | 641.4k $32.6m | Added +38.1k |
| FRANKLIN RESOURCES INC 0.01% of their portfolio | 593.6k $30.2m | Added +241 |
| Nuveen, LLC 0.01% of their portfolio | 590.3k $30.0m | Reduced -64.5k |
| Woodline Partners LP 0.15% of their portfolio | 567.9k $28.9m | Added +1.6k |
| MORGAN STANLEY 0.00% of their portfolio | 566.3k $28.8m | Reduced -40.1k |
| D. E. Shaw & Co., Inc. 0.03% of their portfolio | 555.0k $28.2m | Added +11.7k |
| LOOMIS SAYLES & CO L P 0.04% of their portfolio | 553.0k $28.1m | Reduced -13.2k |
| First Turn Management, LLC 5.01% of their portfolio | 527.5k $26.8m | Added +24.5k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 496.1k $25.2m | Added +249.3k |
| BNP PARIBAS FINANCIAL MARKETS 0.02% of their portfolio | 481.5k $24.5m | Reduced -17.7k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 480.3k $24.4m | Added +192.3k |
| MACQUARIE GROUP LTD 0.03% of their portfolio | 435.7k $22.2m | Added +69.0k |
| Connor, Clark & Lunn Investment Management Ltd. 0.08% of their portfolio | 423.7k $21.6m | Added +67.5k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 402.4k $20.5m | Added +13.5k |
| RENAISSANCE TECHNOLOGIES LLC 0.03% of their portfolio | 396.3k $20.2m | Added +207.8k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 395.0k $20.1m | Reduced -82.6k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 389.3k $19.8m | Added +10.6k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 383.2k $19.5m | Added +55.3k |
| Candriam S.C.A. 0.11% of their portfolio | 373.0k $19.0m | Reduced -10.0k |
| AXA S.A. 0.05% of their portfolio | 351.7k $17.9m | Added +310 |
| FEDERATED HERMES, INC. 0.03% of their portfolio | 344.3k $17.5m | Reduced -3.1k |
| Penn Capital Management Company, LLC 1.51% of their portfolio | 342.3k $17.5m | Reduced -31.3k |
| EMERALD ADVISERS, LLC 0.57% of their portfolio | 305.8k $15.6m | New |
| Soleus Capital Management, L.P. 1.05% of their portfolio | 298.7k $15.2m | New |
| MILLENNIUM MANAGEMENT LLC 0.01% of their portfolio | 288.2k $14.7m | Reduced -191.1k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 264.1k $13.4m | Added +14.8k |
| Erste Asset Management GmbH 0.11% of their portfolio | 260.0k $13.2m | Unchanged |
| Point72 Asset Management, L.P. 0.03% of their portfolio | 258.9k $13.2m | Added +26.8k |
| NEW YORK STATE COMMON RETIREMENT FUND 0.02% of their portfolio | 249.9k $12.7m | Reduced -10.5k |
| Russell Investments Group, Ltd. 0.02% of their portfolio | 247.7k $12.6m | Added +18.3k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.02% of their portfolio | 243.0k $12.4m | Reduced -102.0k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 242.8k $12.4m | Added +46.9k |
| Eversept Partners, LP 1.19% of their portfolio | 232.2k $11.8m | New |
| RICE HALL JAMES & ASSOCIATES, LLC 0.64% of their portfolio | 232.0k $11.8m | Reduced -2.7k |
| EMERALD MUTUAL FUND ADVISERS TRUST 0.67% of their portfolio | 217.5k $11.1m | New |
| Prosight Management, LP 2.48% of their portfolio | 200.0k $10.2m | Reduced -143.3k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 198.2k $10.1m | Added +164.5k |
| NEXT CENTURY GROWTH INVESTORS LLC 0.75% of their portfolio | 190.3k $9.7m | Reduced -5.0k |
| Nicholas Investment Partners, LP 0.84% of their portfolio | 184.5k $9.4m | Added +11.4k |
| UBS Group AG 0.00% of their portfolio | 182.5k $9.3m | Reduced -53.5k |
| TWO SIGMA INVESTMENTS, LP 0.02% of their portfolio | 171.8k $8.7m | Reduced -3.3k |
| TWO SIGMA ADVISERS, LP 0.02% of their portfolio | 171.4k $8.7m | Reduced -35.2k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 161.5k $8.2m | Added +12.0k |
| ALGERT GLOBAL LLC 0.17% of their portfolio | 159.3k $8.1m | Added +92.6k |
| Qube Research & Technologies Ltd 0.01% of their portfolio | 159.0k $8.1m | Added +19.6k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 155.6k $7.9m | Reduced -85.1k |
| BARCLAYS PLC 0.00% of their portfolio | 154.9k $7.9m | Added +73.6k |
| Jump Financial, LLC 0.09% of their portfolio | 148.7k $7.6m | Added +132.9k |
| NAN FUNG TRINITY (HK) LTD 0.89% of their portfolio | 146.8k $7.5m | New |
| PDT Partners, LLC 0.42% of their portfolio | 145.4k $7.4m | Added +7.9k |
| Cubist Systematic Strategies, LLC 0.08% of their portfolio | 144.9k $7.4m | Reduced -151.9k |
| SILVERCREST ASSET MANAGEMENT GROUP LLC 0.05% of their portfolio | 135.9k $6.9m | Unchanged |
| Ensign Peak Advisors, Inc 0.01% of their portfolio | 134.0k $6.8m | Unchanged |
| FIRST TRUST ADVISORS LP 0.01% of their portfolio | 129.8k $6.6m | Added +160 |
| Highlander Partners, L.P. 2.40% of their portfolio | 123.0k $6.3m | Unchanged |
| Hennion & Walsh Asset Management, Inc. 0.25% of their portfolio | 122.8k $6.2m | Reduced -24.4k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 118.6k $6.0m | Added +5.6k |
| Patient Square Capital LP 2.08% of their portfolio | 113.5k $5.8m | Reduced -2.9k |
| ESSEX INVESTMENT MANAGEMENT CO LLC 1.04% of their portfolio | 112.7k $5.7m | New |
| Atle Fund Management AB 2.33% of their portfolio | 106.9k $5.4m | Added +29.6k |
| Trexquant Investment LP 0.06% of their portfolio | 104.3k $5.3m | New |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 0.00% of their portfolio | 75.6k $3.8m | New |
| CITIGROUP INC 0.00% of their portfolio | 70.7k $3.6m | Reduced -63.0k |
| Swiss National Bank 0.00% of their portfolio | 70.2k $3.6m | Added +400 |
| VOYA INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 66.8k $3.4m | Added +27.2k |
| Rhenman & Partners Asset Management AB 0.42% of their portfolio | 65.8k $3.3m | Reduced -8.0k |
| Palo Alto Investors LP 0.70% of their portfolio | 64.7k $3.3m | Unchanged |
| Invesco Ltd. 0.00% of their portfolio | 64.7k $3.3m | Reduced -248.8k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 64.6k $3.3m | Added +9.2k |
| FMR LLC 0.00% of their portfolio | 59.4k $3.0m | Added +5.1k |
| BANK OF MONTREAL /CAN/ 0.00% of their portfolio | 57.0k $2.9m | Added +703 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 52.4k $2.7m | Reduced -4.2k |
| Secure Asset Management, LLC 0.48% of their portfolio | 51.0k $2.6m | Added +2.1k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 47.5k $2.4m | Reduced -1.6k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 43.5k $2.2m | Added +1.6k |
| Legal & General Group Plc 0.00% of their portfolio | 43.0k $2.2m | Added +176 |
| Rafferty Asset Management, LLC 0.01% of their portfolio | 37.2k $1.9m | Reduced -14.7k |
| Aquatic Capital Management LLC 0.04% of their portfolio | 36.9k $1.9m | Reduced -9.4k |
| Phocas Financial Corp. 0.26% of their portfolio | 35.6k $1.8m | Added +5 |
| ExodusPoint Capital Management, LP 0.02% of their portfolio | 34.2k $1.7m | Reduced -2.1k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 33.6k $1.7m | Added +766 |
| Calamos Advisors LLC 0.01% of their portfolio | 33.3k $1.7m | Reduced -3.4k |
| Legato Capital Management LLC 0.19% of their portfolio | 31.8k $1.6m | Added +15.2k |