Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
191 institutional managers reported holding IMNM for the quarter ended Mar 31, 2026. Reported positions total over 95% of shares outstanding; the top 10 hold 67%. 42 opened new positions; 31 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| FMR (Fidelity) | 16.97M | 15.00% | $371.6M | added +2.5% | 2023 Q4 |
| T. Rowe Price Investment Management, INC. | 16.36M | 14.46% | $358.4M | added +1245.1% | 2024 Q1 |
| BlackRock | 8.17M | 7.22% | $178.9M | added +7.6% | 2020 Q4 |
| Vanguard Group | 6.29M | 5.56% | $137.7M | added +4.1% | 2021 Q1 |
| Redmile Group, LLC (focused) | 5.56M | 4.91% | $121.7M | trimmed -2.8% | 2023 Q4 |
| State Street | 5.40M | 4.77% | $118.3M | added +39.6% | 2021 Q1 |
| PRIMECAP Management | 4.79M | 4.23% | $104.9M | added +2.2% | 2024 Q1 |
| Wellington Management | 4.73M | 4.18% | $103.6M | added +406.4% | 2024 Q1 |
| Driehaus Capital Management LLC | 4.10M | 3.62% | $89.8M | added +10.6% | 2025 Q1 |
| Enavate Sciences GP, LLC (focused) | 3.61M | 3.19% | $79.1M | trimmed -24.2% | 2024 Q4 |
| T. Rowe Price | 2.86M | 2.53% | $62.6M | trimmed -15.4% | 2023 Q3 |
| Morgan Stanley | 2.84M | 2.51% | $62.2M | added +66.3% | 2020 Q4 |
| Geode Capital | 2.56M | 2.26% | $56.1M | added +8.4% | 2020 Q4 |
| Silverarc Capital Management, LLC | 1.85M | 1.64% | $40.5M | added +64.3% | 2025 Q4 |
| Sofinnova Investments, INC. | 1.70M | 1.50% | $37.3M | added +5.2% | 2024 Q1 |
| Woodline Partners LP | 1.58M | 1.39% | $34.5M | unchanged | 2023 Q4 |
| Marshall Wace | 1.48M | 1.31% | $32.4M | added +100.9% | 2024 Q1 |
| BNP Paribas Financial Markets | 1.46M | 1.29% | $32.0M | added +654.7% | 2024 Q4 |
| Principal Financial Group INC | 1.38M | 1.22% | $30.2M | trimmed -2% | 2025 Q2 |
| Readystate Asset Management LP | 1.30M | 1.15% | $28.5M | trimmed -29.4% | 2025 Q1 |
| Jefferies Financial Group INC. | 1.16M | 1.03% | $25.4M | trimmed -42% | 2024 Q1 |
| Goldman Sachs | 1.10M | 0.97% | $24.1M | added +46.3% | 2024 Q1 |
| Northern Trust | 899.1k | 0.80% | $19.7M | added +8.5% | 2020 Q4 |
| Charles Schwab Investment Management | 851.8k | 0.75% | $18.7M | added +1.3% | 2024 Q1 |
| Polar Capital Holdings PLC | 849.5k | 0.75% | $18.6M | added +7.1% | 2025 Q2 |
| Janus Henderson | 808.0k | 0.71% | $17.7M | trimmed -2.9% | 2023 Q4 |
| Bank OF America CORP /DE/ | 781.6k | 0.69% | $17.1M | added +285.6% | 2023 Q3 |
| Pivotal bioVenture Partners Investment Advisor LLC (focused) | 732.5k | 0.65% | $16.0M | unchanged | 2025 Q3 |
| NAN Fung Trinity (HK) LTD | 714.6k | 0.63% | $15.6M | unchanged | 2025 Q2 |
| TD Asset Management INC | 694.9k | 0.61% | $15.2M | trimmed -8.5% | 2023 Q3 |
| UBS | 619.9k | 0.55% | $13.6M | added +43.9% | 2020 Q4 |
| Candriam S.c.a. | 539.9k | 0.48% | $11.8M | unchanged | 2025 Q2 |
| Parkman Healthcare Partners LLC | 403.5k | 0.36% | $8.8M | added +45.2% | 2025 Q3 |
| Rock Springs Capital Management LP | 347.7k | 0.31% | $7.6M | unchanged | 2025 Q4 |
| Granahan Investment Management, LLC | 307.0k | 0.27% | $6.7M | trimmed -29.4% | 2024 Q4 |
| Atom Investors LP | 306.9k | 0.27% | $6.7M | added +74.6% | 2025 Q4 |
| Nuveen | 305.3k | 0.27% | $6.7M | added +80.3% | 2024 Q2 |
| Kennedy Capital Management LLC | 287.0k | 0.25% | $6.3M | unchanged | 2024 Q4 |
| BNY Mellon | 276.1k | 0.24% | $6.0M | added +4.8% | 2023 Q4 |
| Tidal Investments LLC | 275.9k | 0.24% | $6.0M | opened | 2026 Q1 |
| Tema ETFs LLC | 275.9k | 0.24% | $6.0M | added +170.3% | 2025 Q2 |
| Atika Capital Management LLC | 262.9k | 0.23% | $5.8M | trimmed -21.4% | 2025 Q4 |
| Balyasny Asset Management | 251.4k | 0.22% | $5.5M | trimmed -82.4% | 2025 Q2 |
| Universal- Beteiligungs- und Servicegesellschaft mbH | 230.7k | 0.20% | $5.1M | added +35.7% | 2025 Q4 |
| Manufacturers Life Insurance Company, THE | 206.8k | 0.18% | $4.5M | trimmed -12.8% | 2023 Q3 |
| Burkehill Global Management, LP | 200.0k | 0.18% | $4.4M | unchanged | 2025 Q4 |
| Qube Research & Technologies LTD | 188.2k | 0.17% | $4.1M | opened | 2025 Q3 |
| Swiss National Bank | 185.0k | 0.16% | $4.1M | unchanged | 2024 Q1 |
| Gilder Gagnon Howe & CO LLC | 169.3k | 0.15% | $3.7M | trimmed -3.2% | 2025 Q3 |
| Trexquant Investment LP | 166.8k | 0.15% | $3.7M | added +27.5% | 2025 Q4 |
Largest 50 of 191 shown; the full ranked, searchable register is at boothcheck.com/holders/IMNM. Related filers are grouped using the filings' own included-manager declarations. Historically, several managers opening new positions in the same quarter said almost nothing about the quarter that followed (59,118 cases since 2013). A filed record, not a forecast. Nothing here is investment advice.