SEPTERNA INC SEPN
COM · Common Stock · CUSIP 81734D104
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersSouth San Francisco, CA
- 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 ($37.6k this quarter). Holder counts are more reliable. Shares outstanding: 44.6m as of 2025-08-04, 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 ≈ $10.57. Options: 5 managers hold calls ($439.7k notional), 6 hold puts ($12.6m).
Trends to Q2 2025
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q4 2024 | 72 |
| Q1 2025 | 72 |
| Q2 2025 | 90 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q1 2025 | 44 | 29 |
| Q2 2025 | 56 | 25 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2024 | $0 | $0 | — |
| Q4 2024 | $0 | $0 | — |
| Q1 2025 | $156.8k | $444.1k | 2.83 |
| Q2 2025 | $439.7k | $12.6m | 28.61 |
Biggest buyers
| Driehaus Capital Management LLC | Added | +1.6m |
| PERCEPTIVE ADVISORS LLC | New | +541.5k |
| Venrock Adviser, LLC | New | +540.5k |
| VANGUARD GROUP INC | Added | +419.3k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | +141.3k |
| BlackRock, Inc. | Added | +132.5k |
| ADAR1 Capital Management, LLC | Added | +126.4k |
| Universal- Beteiligungs- und Servicegesellschaft mbH | Added | +120.0k |
| BANK OF AMERICA CORP /DE/ | Added | +87.7k |
| GEODE CAPITAL MANAGEMENT, LLC | Added | +78.3k |
Biggest sellers
| Deep Track Capital, LP | Reduced | -1.8m |
| Catalio Capital Management, LP | Reduced | -729.9k |
| Soleus Capital Management, L.P. | Reduced | -675.9k |
| MILLENNIUM MANAGEMENT LLC | Reduced | -384.6k |
| Woodline Partners LP | Reduced | -300.0k |
| Checkpoint Capital L.P. | Reduced | -238.4k |
| Sio Capital Management, LLC | Reduced | -204.2k |
| UBS Group AG | Reduced | -167.6k |
| Avoro Capital Advisors LLC | Reduced | -100.0k |
| Stonepine Capital Management, LLC | Sold out | -68.1k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $291.7k27.6k shares |
| CITADEL ADVISORS LLC | Added | $125.8k11.9k shares |
| SIMPLEX TRADING, LLC | Added | $19.0k1.8k shares |
| GROUP ONE TRADING LLC | New | $3.2k300 shares |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | Unchanged | $00 shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $5.6m528.1k shares |
| JANE STREET GROUP, LLC | Added | $4.7m448.3k shares |
| CITADEL ADVISORS LLC | Added | $1.1m100.6k shares |
| SIMPLEX TRADING, LLC | New | $1.0m98.6k shares |
| GROUP ONE TRADING LLC | New | $153.3k14.5k 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 |
|---|---|
| Third Rock Ventures V, L.P. 13G · exempt (held before listing) no change · filed 2025-05-09 | 14.0% |
| RA CAPITAL MANAGEMENT, L.P. 13D · may seek influence filed 2026-08-14 | 11.8% |
| DRIEHAUS CAPITAL MANAGEMENT LLC 13G · institution -0.6 pts · filed 2026-08-14 | 9.8% |
Fell to 5% or below in the last year: BIOTECHNOLOGY VALUE FUND L P (3.8%, 2026-02-17)
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 | 0 | — | 0 | — | — |
| Q4 2023 | 0 | — | 0 | — | — |
| Q1 2024 | 0 | — | 0 | — | — |
| Q2 2024 | 0 | — | 0 | — | — |
| Q3 2024 | 0 | — | 0 | — | — |
| Q4 2024 | 1 | $75.1m | 0 | — | — |
| Q1 2025 | 3 | $934.4k | 0 | — | — |
| Q2 2025 | 0 | — | 0 | — | — |
None reported in Q2 2025.
Holders, Q2 2025
| Manager | Shares | Change |
|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. 1.25% of their portfolio | 7.0m $73.9m | Unchanged |
| TRV GP V, LLC 39.66% of their portfolio | 6.2m $65.7m | Unchanged |
| Driehaus Capital Management LLC 0.40% of their portfolio | 4.7m $49.5m | Added +1.6m |
| BVF INC/IL 1.66% of their portfolio | 4.4m $46.5m | Unchanged |
| TRV GP VI, LLC 69.32% of their portfolio | 4.2m $44.5m | Unchanged |
| SAMSARA BIOCAPITAL, LLC 6.81% of their portfolio | 3.1m $33.3m | Unchanged |
| Siren, L.L.C. 1.20% of their portfolio | 2.2m $23.3m | Unchanged |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 1.4m $15.0m | Reduced -33.1k |
| VANGUARD GROUP INC 0.00% of their portfolio | 1.4m $14.9m | Added +419.3k |
| BlackRock, Inc. 0.00% of their portfolio | 1.4m $14.7m | Added +132.5k |
| Avoro Capital Advisors LLC 0.23% of their portfolio | 1.2m $13.1m | Reduced -100.0k |
| ADAR1 Capital Management, LLC 1.45% of their portfolio | 847.2k $9.0m | Added +126.4k |
| Checkpoint Capital L.P. 2.89% of their portfolio | 586.5k $6.2m | Reduced -238.4k |
| Sio Capital Management, LLC 2.48% of their portfolio | 584.4k $6.2m | Reduced -204.2k |
| Casdin Capital, LLC 0.53% of their portfolio | 553.3k $5.8m | Unchanged |
| PERCEPTIVE ADVISORS LLC 0.21% of their portfolio | 541.5k $5.7m | New |
| Venrock Adviser, LLC 0.43% of their portfolio | 540.5k $5.7m | New |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 488.0k $5.2m | Added +78.3k |
| STATE STREET CORP 0.00% of their portfolio | 370.0k $3.9m | Added +25.4k |
| Catalio Capital Management, LP 0.65% of their portfolio | 294.4k $3.1m | Reduced -729.9k |
| Woodline Partners LP 0.02% of their portfolio | 282.6k $3.0m | Reduced -300.0k |
| Universal- Beteiligungs- und Servicegesellschaft mbH 0.00% of their portfolio | 222.7k $2.4m | Added +120.0k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 166.5k $1.8m | Added +141.3k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 154.8k $1.6m | Added +36.3k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 154.3k $1.6m | Reduced -3.7k |
| Deep Track Capital, LP 0.04% of their portfolio | 121.7k $1.3m | Reduced -1.8m |
| Logos Global Management LP 0.15% of their portfolio | 109.2k $1.2m | Reduced -25.0k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 99.2k $1.0m | Added +87.7k |
| MORGAN STANLEY 0.00% of their portfolio | 84.9k $897.0k | Reduced -6.2k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 77.6k $820.7k | Added +2.8k |
| Soleus Capital Management, L.P. 0.06% of their portfolio | 75.5k $797.6k | Reduced -675.9k |
| UBS Group AG 0.00% of their portfolio | 72.3k $764.6k | Reduced -167.6k |
| Rangeley Capital, LLC 0.78% of their portfolio | 58.6k $619.5k | Added +5.7k |
| Nuveen, LLC 0.00% of their portfolio | 58.0k $612.8k | Added +34.0k |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 51.9k $549.0k | Reduced -384.6k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 48.5k $512.5k | Added +10.1k |
| BARCLAYS PLC 0.00% of their portfolio | 35.7k $377.4k | Added +13.0k |
| Alyeska Investment Group, L.P. 0.00% of their portfolio | 35.0k $369.9k | Unchanged |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 28.7k $303.4k | New |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 28.6k $302.0k | Added +5.3k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 24.9k $264.0k | Added +1.9k |
| BOOTHBAY FUND MANAGEMENT, LLC 0.01% of their portfolio | 24.1k $255.2k | New |
| GSA CAPITAL PARTNERS LLP 0.02% of their portfolio | 23.5k $249.0k | Added +5.2k |
| SIMPLEX TRADING, LLC 0.01% of their portfolio | 23.5k $248.0k | Added +23.5k |
| XTX Topco Ltd 0.01% of their portfolio | 22.3k $236.0k | Reduced -15.0k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 22.1k $233.6k | New |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 17.8k $187.9k | New |
| TUDOR INVESTMENT CORP ET AL 0.00% of their portfolio | 16.8k $177.2k | New |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 14.7k $155.6k | Added +3.8k |
| MetLife Investment Management, LLC 0.00% of their portfolio | 13.7k $144.7k | New |
| CW Advisors, LLC 0.00% of their portfolio | 12.6k $133.1k | New |
| INTECH INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 12.2k $129.0k | New |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 12.1k $128.1k | Reduced -3.8k |
| Invesco Ltd. 0.00% of their portfolio | 11.8k $125.1k | Reduced -369 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 11.7k $123.6k | Added +710 |
| Squarepoint Ops LLC 0.00% of their portfolio | 10.7k $113.5k | New |
| PharVision Advisers, LLC 0.15% of their portfolio | 10.2k $107.3k | New |
| Quadrature Capital Ltd 0.00% of their portfolio | 10.1k $107.3k | New |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 10.1k $106.8k | Added +1.3k |
| CITIGROUP INC 0.00% of their portfolio | 7.2k $75.8k | Reduced -30.9k |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 3.7k $38.0k | Added +2.9k |
| Quarry LP 0.01% of their portfolio | 3.6k $38.1k | New |
| Police & Firemen's Retirement System of New Jersey 0.00% of their portfolio | 3.6k $37.6k | Unchanged |
| STRS OHIO 0.00% of their portfolio | 3.4k $35.9k | Unchanged |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 2.9k $30.7k | Unchanged |
| FMR LLC 0.00% of their portfolio | 2.5k $26.3k | Reduced -47.3k |
| Covestor Ltd 0.01% of their portfolio | 2.3k $24.0k | Added +2.3k |
| Tower Research Capital LLC (TRC) 0.00% of their portfolio | 2.2k $23.5k | Added +437 |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 2.2k $23.4k | Added +1.1k |
| Legal & General Group Plc 0.00% of their portfolio | 1.9k $20.6k | Added +105 |
| Ameritas Investment Partners, Inc. 0.00% of their portfolio | 1.9k $20.5k | Unchanged |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 1.4k $14.5k | Reduced -43.0k |
| SIGNATUREFD, LLC 0.00% of their portfolio | 966 $10.2k | New |
| CWM, LLC 0.00% of their portfolio | 872 $9.0k | Added +590 |
| GROUP ONE TRADING LLC 0.00% of their portfolio | 789 $8.3k | New |
| AMALGAMATED BANK 0.00% of their portfolio | 634 $7.0k | Unchanged |
| Caitong International Asset Management Co., Ltd 0.00% of their portfolio | 605 $6.4k | New |
| Sterling Capital Management LLC 0.00% of their portfolio | 577 $6.1k | Added +420 |
| GAMMA Investing LLC 0.00% of their portfolio | 577 $6.1k | Added +143 |
| US BANCORP \DE\ 0.00% of their portfolio | 265 $2.8k | New |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 222 $2.3k | New |
| OSAIC HOLDINGS, INC. 0.00% of their portfolio | 214 $2.3k | New |
| COMERICA BANK 0.00% of their portfolio | 212 $2.2k | New |
| NISA INVESTMENT ADVISORS, LLC 0.00% of their portfolio | 143 $1.5k | Added +9 |
| Fortitude Family Office, LLC 0.00% of their portfolio | 71 $750 | New |
| SBI Securities Co., Ltd. 0.00% of their portfolio | 50 $529 | New |
| ROTHSCHILD INVESTMENT LLC 0.00% of their portfolio | 30 $317 | New |
| EverSource Wealth Advisors, LLC 0.00% of their portfolio | 22 $233 | New |
| NATIONAL BANK OF CANADA /FI/ 0.00% of their portfolio | 8 $85 | Unchanged |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. — of their portfolio | 0 $0 | Unchanged |