Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
274 institutional managers reported holding RYTM for the quarter ended Mar 31, 2026. Reported positions total over 95% of shares outstanding; the top 10 hold 57%. 56 opened new positions; 58 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| RA Capital Management, L.p. | 6.67M | 9.81% | $580.0M | unchanged | 2018 Q2 |
| Vanguard Group | 6.53M | 9.60% | $567.8M | added +5% | 2017 Q4 |
| BlackRock | 6.24M | 9.18% | $542.6M | trimmed -1% | 2017 Q4 |
| Baker Bros. Advisors LP | 5.60M | 8.24% | $487.6M | unchanged | 2017 Q4 |
| PRIMECAP Management | 3.42M | 5.03% | $297.3M | trimmed -1.8% | 2019 Q3 |
| Perceptive Advisors LLC | 2.37M | 3.49% | $206.5M | trimmed -6.8% | 2023 Q3 |
| State Street | 2.27M | 3.34% | $197.7M | added +3.3% | 2017 Q4 |
| Goldman Sachs | 1.97M | 2.89% | $171.0M | added +7.3% | 2018 Q2 |
| Westfield Capital Management CO LP | 1.93M | 2.84% | $167.8M | added +52.2% | 2025 Q1 |
| FMR (Fidelity) | 1.69M | 2.49% | $147.0M | trimmed -1% | 2017 Q4 |
| T. Rowe Price | 1.65M | 2.44% | $144.0M | added +6% | 2020 Q4 |
| Polar Capital Holdings PLC | 1.62M | 2.38% | $140.6M | added +36.3% | 2022 Q3 |
| Citadel Advisors | 1.42M | 2.09% | $123.4M | added +825.3% | 2022 Q1 |
| Geode Capital | 1.42M | 2.08% | $123.2M | added +2.9% | 2017 Q4 |
| Federated Hermes, INC. | 1.29M | 1.89% | $111.9M | trimmed -20.8% | 2018 Q1 |
| Checkpoint Capital L.p. (focused) | 1.23M | 1.80% | $106.8M | added +23.7% | 2023 Q4 |
| Capital Research Global Investors | 1.12M | 1.64% | $97.0M | added +13.2% | 2025 Q3 |
| Janus Henderson | 918.2k | 1.35% | $79.9M | trimmed -18.5% | 2017 Q4 |
| AllianceBernstein | 910.4k | 1.34% | $79.2M | trimmed -2.1% | 2023 Q2 |
| Point72 | 846.8k | 1.25% | $73.7M | added +97.2% | 2025 Q1 |
| UBS | 773.1k | 1.14% | $67.3M | trimmed -20.8% | 2017 Q4 |
| Woodline Partners LP | 758.9k | 1.12% | $66.0M | added +10.2% | 2025 Q2 |
| Adage Capital Partners GP, L.l.c. | 725.7k | 1.07% | $63.1M | added +16.8% | 2025 Q2 |
| Siren, L.l.c. | 725.5k | 1.07% | $63.1M | added +45.1% | 2025 Q1 |
| Morgan Stanley | 704.0k | 1.04% | $61.2M | added +8.1% | 2017 Q4 |
| Rock Springs Capital Management LP | 689.7k | 1.01% | $60.0M | trimmed -0.8% | 2017 Q4 |
| Pictet Asset Management Holding SA | 667.0k | 0.98% | $58.0M | added +8.5% | 2023 Q4 |
| Bank OF America CORP /DE/ | 628.7k | 0.93% | $54.7M | added +180% | 2017 Q4 |
| Franklin Resources | 626.8k | 0.92% | $54.5M | trimmed -9.9% | 2023 Q4 |
| Clearbridge Investments, LLC | 609.4k | 0.90% | $53.0M | added +20.4% | 2025 Q2 |
| Integral Health Asset Management, LLC | 600.0k | 0.88% | $52.2M | added +26.3% | 2024 Q4 |
| Charles Schwab Investment Management | 526.5k | 0.77% | $45.8M | trimmed -1.1% | 2017 Q4 |
| Northern Trust | 498.5k | 0.73% | $43.4M | added +2.1% | 2017 Q4 |
| Loomis Sayles & CO L P | 465.1k | 0.68% | $40.5M | trimmed -7.7% | 2024 Q3 |
| Candriam S.c.a. | 464.3k | 0.68% | $40.4M | added +61.3% | 2024 Q2 |
| Millennium Management | 451.8k | 0.67% | $39.3M | added +142% | 2024 Q3 |
| Sofinnova Investments, INC. | 450.1k | 0.66% | $39.2M | added +65.8% | 2024 Q3 |
| Logos Global Management LP | 450.0k | 0.66% | $39.1M | added +136.8% | 2025 Q2 |
| Driehaus Capital Management LLC | 436.5k | 0.64% | $38.0M | trimmed -66% | 2022 Q3 |
| Artisan Partners | 390.7k | 0.57% | $34.0M | added +48.2% | 2025 Q2 |
| Ameriprise Financial INC | 384.0k | 0.56% | $33.4M | added +47% | 2022 Q2 |
| Invesco | 364.3k | 0.54% | $31.7M | added +25.1% | 2022 Q4 |
| Lord, Abbett & CO. LLC | 349.0k | 0.51% | $30.4M | trimmed -43.7% | 2023 Q4 |
| Orbimed Advisors LLC | 314.1k | 0.46% | $27.3M | added +31% | 2023 Q3 |
| Braidwell LP | 310.6k | 0.46% | $27.0M | opened | 2026 Q1 |
| Silverarc Capital Management, LLC | 306.0k | 0.45% | $26.6M | added +125.1% | 2023 Q2 |
| BNY Mellon | 293.3k | 0.43% | $25.5M | trimmed -2.6% | 2017 Q4 |
| BNP Paribas Financial Markets | 291.7k | 0.43% | $25.4M | added +74.7% | 2017 Q4 |
| Qube Research & Technologies LTD | 277.9k | 0.41% | $24.2M | trimmed -10.6% | 2024 Q4 |
| Wellington Management | 273.8k | 0.40% | $23.8M | added +9.4% | 2017 Q4 |
Largest 50 of 274 shown; the full ranked, searchable register is at boothcheck.com/holders/RYTM. 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.