Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
280 institutional managers reported holding XENE for the quarter ended Mar 31, 2026. Reported positions total over 95% of shares outstanding; the top 10 hold 54%. 73 opened new positions; 37 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| FMR (Fidelity) | 10.82M | 12.39% | $628.9M | added +21.3% | 2020 Q1 |
| Avoro Capital Advisors LLC (focused) | 5.78M | 6.62% | $335.9M | added +6.5% | 2018 Q2 |
| BlackRock | 5.64M | 6.46% | $327.9M | added +10.6% | 2018 Q4 |
| Wellington Management | 4.83M | 5.53% | $280.8M | added +1.4% | 2023 Q1 |
| Driehaus Capital Management LLC | 4.49M | 5.14% | $261.1M | trimmed -1% | 2020 Q1 |
| Polar Capital Holdings PLC | 4.41M | 5.04% | $256.1M | added +78.7% | 2021 Q4 |
| Janus Henderson | 4.18M | 4.78% | $242.8M | added +2.3% | 2022 Q1 |
| Capital International Investors | 2.67M | 3.06% | $155.5M | trimmed -21.7% | 2018 Q3 |
| Citadel Advisors | 2.65M | 3.04% | $154.2M | added +100.8% | 2018 Q3 |
| State Street | 1.72M | 1.97% | $100.0M | added +15.3% | 2018 Q3 |
| Affinity Asset Advisors, LLC | 1.68M | 1.92% | $97.4M | added +34% | 2022 Q4 |
| Deerfield Management Company, L.p. | 1.62M | 1.85% | $93.9M | added +198.1% | 2025 Q2 |
| Holocene Advisors | 1.52M | 1.74% | $88.3M | added +18.5% | 2025 Q2 |
| BNP Paribas Financial Markets | 1.42M | 1.63% | $82.7M | added +23.3% | 2020 Q3 |
| AllianceBernstein | 1.40M | 1.61% | $81.6M | trimmed -12% | 2021 Q2 |
| Westfield Capital Management CO LP | 1.40M | 1.60% | $81.5M | added +14.2% | 2023 Q4 |
| Caligan Partners LP (focused) | 1.39M | 1.59% | $81.0M | added +153.4% | 2025 Q3 |
| Braidwell LP | 1.34M | 1.53% | $77.8M | trimmed -26.7% | 2022 Q4 |
| T. Rowe Price | 1.33M | 1.52% | $77.3M | added +54.2% | 2025 Q2 |
| Jennison Associates LLC | 1.32M | 1.51% | $76.7M | added +2.1% | 2023 Q2 |
| Siren, L.l.c. | 1.32M | 1.51% | $76.7M | added +62.2% | 2024 Q3 |
| Alyeska Investment Group | 1.30M | 1.49% | $75.5M | opened | 2026 Q1 |
| Franklin Resources | 1.28M | 1.47% | $74.4M | added +68.9% | 2023 Q1 |
| Geode Capital | 1.09M | 1.25% | $63.5M | added +14.7% | 2018 Q4 |
| Orbimed Advisors LLC | 1.06M | 1.21% | $61.6M | added +137% | 2016 Q3 |
| Federated Hermes, INC. | 972.2k | 1.11% | $56.5M | added +44.6% | 2023 Q4 |
| T. Rowe Price Investment Management, INC. | 952.0k | 1.09% | $55.3M | added +928.6% | 2023 Q4 |
| Capital Group (American Funds) | 840.1k | 0.96% | $48.8M | added +28.1% | 2014 Q4 |
| Commodore Capital LP (focused) | 825.0k | 0.94% | $48.0M | trimmed -54.2% | 2020 Q4 |
| Vanguard Group | 787.8k | 0.90% | $45.8M | added +17.7% | 2020 Q2 |
| First Turn Management, LLC (focused) | 786.8k | 0.90% | $45.7M | trimmed -1.6% | 2023 Q4 |
| Goldman Sachs | 769.9k | 0.88% | $44.8M | added +10.6% | 2018 Q4 |
| Rock Springs Capital Management LP | 763.0k | 0.87% | $44.4M | trimmed -3.1% | 2020 Q1 |
| Fiera Capital CORP | 709.5k | 0.81% | $41.2M | added +3.4% | 2023 Q2 |
| Pictet Asset Management Holding SA | 679.7k | 0.78% | $39.5M | added +8.6% | 2022 Q1 |
| American Century Companies INC | 679.3k | 0.78% | $39.5M | unchanged | 2025 Q2 |
| Vestal Point Capital, LP | 639.9k | 0.73% | $37.2M | added +6.7% | 2023 Q4 |
| Aberdeen Group plc | 609.9k | 0.70% | $35.5M | trimmed -18.7% | 2023 Q4 |
| Two Sigma | 606.1k | 0.69% | $35.2M | added +38.8% | 2025 Q4 |
| MPM Bioimpact LLC (focused) | 588.7k | 0.67% | $34.2M | added +21.2% | 2024 Q3 |
| Loomis Sayles & CO L P | 564.9k | 0.65% | $32.8M | trimmed -7.7% | 2022 Q4 |
| Northern Trust | 527.8k | 0.60% | $30.7M | added +20.3% | 2018 Q3 |
| Parkman Healthcare Partners LLC | 497.0k | 0.57% | $28.9M | added +222.4% | 2019 Q4 |
| Tudor Investment | 495.6k | 0.57% | $28.8M | added +95.1% | 2025 Q3 |
| Octagon Capital Advisors LP (focused) | 490.0k | 0.56% | $28.5M | opened | 2026 Q1 |
| Novo Holdings A/S (focused) | 485.4k | 0.56% | $28.2M | opened | 2026 Q1 |
| Candriam S.c.a. | 476.5k | 0.55% | $27.7M | added +14.2% | 2021 Q2 |
| UBS | 474.8k | 0.54% | $27.6M | added +799.6% | 2018 Q2 |
| Morgan Stanley | 473.8k | 0.54% | $27.5M | added +61% | 2014 Q4 |
| Adage Capital Partners GP, L.l.c. | 470.0k | 0.54% | $27.3M | trimmed -31.4% | 2018 Q2 |
Largest 50 of 280 shown; the full ranked, searchable register is at boothcheck.com/holders/XENE. 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.