Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
269 institutional managers reported holding ASND for the quarter ended Mar 31, 2026. Reported positions total over 95% of shares outstanding; the top 10 hold 68%. 31 opened new positions; 50 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. | 10.28M | 16.92% | $2.35B | unchanged | 2015 Q1 |
| T. Rowe Price Investment Management, INC. | 6.16M | 10.14% | $1.41B | added +470.4% | 2022 Q3 |
| Avoro Capital Advisors LLC (focused) | 5.06M | 8.33% | $1.16B | trimmed -1% | 2016 Q3 |
| Westfield Capital Management CO LP | 4.81M | 7.92% | $1.10B | trimmed -7.2% | 2018 Q2 |
| FMR (Fidelity) | 3.88M | 6.38% | $886.4M | trimmed -6.7% | 2015 Q1 |
| Artisan Partners | 3.23M | 5.32% | $738.6M | unchanged | 2018 Q2 |
| Franklin Resources | 2.05M | 3.38% | $469.2M | added +7.4% | 2018 Q1 |
| Capital International Investors | 1.96M | 3.22% | $447.9M | trimmed -36.1% | 2022 Q1 |
| MFS Investment Management | 1.86M | 3.06% | $425.4M | trimmed -1.4% | 2020 Q3 |
| Wellington Management | 1.76M | 2.89% | $401.9M | unchanged | 2018 Q1 |
| Perceptive Advisors LLC | 1.53M | 2.52% | $350.2M | added +41.6% | 2025 Q2 |
| T. Rowe Price | 1.53M | 2.52% | $349.9M | trimmed -2.5% | 2017 Q4 |
| American Century Companies INC | 1.40M | 2.30% | $319.5M | trimmed -3.2% | 2021 Q1 |
| Capital Group (American Funds) | 900.5k | 1.48% | $205.9M | opened | 2026 Q1 |
| Principal Financial Group INC | 896.4k | 1.48% | $205.0M | trimmed -12.7% | 2024 Q3 |
| BlackRock | 661.1k | 1.09% | $151.1M | added +5.2% | 2017 Q4 |
| Polar Capital Holdings PLC | 651.7k | 1.07% | $149.0M | added +75.9% | 2024 Q3 |
| Morgan Stanley | 606.3k | 1.00% | $138.6M | trimmed -1.9% | 2016 Q4 |
| Goldman Sachs | 566.2k | 0.93% | $129.5M | trimmed -5.1% | 2017 Q4 |
| Nomura Asset Management International INC. | 556.4k | 0.92% | $127.2M | added +12% | 2025 Q4 |
| Ameriprise Financial INC | 476.5k | 0.78% | $108.9M | trimmed -13.4% | 2019 Q1 |
| FIL LTD | 447.4k | 0.74% | $102.3M | trimmed -6.5% | 2023 Q4 |
| Vestal Point Capital, LP | 375.0k | 0.62% | $85.7M | added +114.3% | 2023 Q4 |
| Invesco | 362.1k | 0.60% | $82.8M | trimmed -38.2% | 2018 Q2 |
| SEI Investments CO | 351.1k | 0.58% | $80.3M | added +24.8% | 2019 Q1 |
| BNP Paribas Financial Markets | 309.2k | 0.51% | $70.7M | trimmed -18.5% | 2021 Q4 |
| Fred Alger Management, LLC | 304.9k | 0.50% | $69.7M | trimmed -13.4% | 2022 Q4 |
| AllianceBernstein | 278.2k | 0.46% | $63.6M | trimmed -3.6% | 2017 Q3 |
| Tri Locum Partners LP (focused) | 255.3k | 0.42% | $58.4M | trimmed -3.7% | 2025 Q1 |
| Pictet Asset Management Holding SA | 251.8k | 0.41% | $57.6M | added +243% | 2023 Q2 |
| Candriam S.c.a. | 230.3k | 0.38% | $52.7M | added +23.2% | 2019 Q3 |
| BNY Mellon | 228.7k | 0.38% | $52.3M | added +17.5% | 2019 Q4 |
| Two Sigma | 220.3k | 0.36% | $50.4M | trimmed -11.1% | 2024 Q1 |
| TD Asset Management INC | 218.0k | 0.36% | $49.8M | trimmed -6.8% | 2017 Q4 |
| Aberdeen Group plc | 210.2k | 0.35% | $48.1M | trimmed -5.2% | 2023 Q4 |
| ARS Investment Partners, LLC | 209.5k | 0.34% | $47.9M | added +20% | 2019 Q4 |
| UBS | 207.4k | 0.34% | $47.4M | trimmed -32.7% | 2015 Q1 |
| Bank OF America CORP /DE/ | 198.5k | 0.33% | $45.4M | added +22.2% | 2015 Q1 |
| Rock Springs Capital Management LP | 194.0k | 0.32% | $44.4M | trimmed -4.7% | 2015 Q1 |
| Millennium Management | 189.0k | 0.31% | $43.2M | trimmed -27.9% | 2023 Q3 |
| Allspring Global Investments Holdings, LLC | 184.2k | 0.30% | $42.1M | trimmed -1.8% | 2021 Q4 |
| Orbimed Advisors LLC | 182.0k | 0.30% | $41.6M | added +5.8% | 2025 Q2 |
| NEW York State Common Retirement Fund | 171.1k | 0.28% | $39.1M | trimmed -6.1% | 2018 Q1 |
| Wells Fargo & COMPANY/MN | 154.2k | 0.25% | $35.3M | added +356.5% | 2016 Q4 |
| PFM Health Sciences, LP | 152.0k | 0.25% | $34.8M | trimmed -14.4% | 2024 Q3 |
| Rice Hall James & Associates, LLC | 148.4k | 0.24% | $33.9M | added +2.3% | 2020 Q3 |
| Lord, Abbett & CO. LLC | 145.3k | 0.24% | $33.2M | added +20.9% | 2025 Q2 |
| Deutsche Bank AG\ | 135.2k | 0.22% | $30.9M | trimmed -54.5% | 2017 Q1 |
| Frazier Life Sciences Management, L.p. (focused) | 133.3k | 0.22% | $30.5M | unchanged | 2024 Q3 |
| Braun Stacey Associates INC | 131.0k | 0.22% | $30.0M | added +10% | 2025 Q3 |
Largest 50 of 269 shown; the full ranked, searchable register is at boothcheck.com/holders/ASND. 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.