🕵️ Septerna, Inc. ($SEPN)
SEC insider & ownership activity, last 12 months · CIK 1984086 · every row links its SEC filing
Over the last 12 months insiders sold $76.1M with no open-market buying against it. RA Capital Management, L.P. sold $63.5M in discretionary trades (Aug). 2 planned sales are pending, the largest $3.3M (Jae Kim). No red-flag 8-Ks in the window.
Monthly net open-market insider flow, last 12 months (up = net buying)
Insider flow
0 buyers, $0 (0 lots) · 5 sellers, $76.1M (27 lots)
| Insider | Buys | Bought | Sells | Sold | Last |
|---|---|---|---|---|---|
| RA Capital Management, L.P. | 0 | – | 2 | $63.5M | Aug 12, 2026 |
| Third Rock Ventures V, L.P. | 0 | – | 2 | $7.4M | Aug 12, 2026 |
| Shaikhly Samira | 0 | – | 8 | $2.8M | Jun 29, 2026 |
| Elizabeth Bhatt | 0 | – | 7 | $1.4M | Aug 11, 2026 |
| Daniel D. Long | 0 | – | 8 | $951K | Sep 1, 2026 |
5%+ holders
| Holder | Stake | Class | Schedule | Event | |
|---|---|---|---|---|---|
| Third Rock Ventures V, L.P. | 14.0% | 13G | May 9, 2025 | filing ↗ | |
| Third Rock Ventures GP V, L.P. | 14.0% | 13G | May 9, 2025 | filing ↗ | |
| TRV GP V, LLC | 14.0% | 13G | May 9, 2025 | filing ↗ | |
| RA Capital Management, L.P. | 11.8% | 13D | Aug 12, 2026 | filing ↗ | |
| Peter Kolchinsky | 11.8% | 13D | Aug 12, 2026 | filing ↗ | |
| Rajeev Shah | 11.8% | 13D | Aug 12, 2026 | filing ↗ | |
| RA Capital Healthcare Fund, L.P. | 10.2% | 13D | Aug 12, 2026 | filing ↗ | |
| Driehaus Capital Management LLC | 9.8% | 13G | Aug 14, 2026 | filing ↗ | |
| Third Rock Ventures VI, L.P. | 9.5% | 13G | May 9, 2025 | filing ↗ | |
| Third Rock Ventures GP VI, L.P. | 9.5% | 13G | May 9, 2025 | filing ↗ | |
| TRV GP VI, LLC | 9.5% | 13G | May 9, 2025 | filing ↗ |
Planned insider sales (Form 144)
| Seller | Planned | Approx. sale date | |
|---|---|---|---|
| Third Rock Ventures V, L.P. | $7.5M | Aug 12, 2026 | filing ↗ |
| RA Capital Healthcare Fund LP | $36.0M | Aug 12, 2026 | filing ↗ |
| RA Capital Nexus Fund III, L.P. | $36.0M | Aug 12, 2026 | filing ↗ |
| Elizabeth P. Bhatt | $1.1M | Aug 11, 2026 | filing ↗ |
| Elizabeth P. Bhatt | $138K | Jul 15, 2026 | filing ↗ |
| Jae Kim | $89K | Jun 26, 2026 | filing ↗ |
| Daniel Long | $904K | Jun 22, 2026 | filing ↗ |
| Jae Kim | $3.3M | Jun 22, 2026 | filing ↗ |
| Samira Shaikhly | $287K | Jun 12, 2026 | filing ↗ |
| Samira Shaikhly | $335K | May 26, 2026 | filing ↗ |
| Samira Shaikhly | $2.2M | Mar 2, 2026 | filing ↗ |
| Elizabeth Bhatt | $242K | Feb 18, 2026 | filing ↗ |
| Daniel David Long | $63K | Nov 10, 2025 | filing ↗ |
Material events (8-K)
| Item | Event date | |
|---|---|---|
| Reg FD disclosure (7.01) | Aug 22, 2026 | filing ↗ |
| Other events (8.01) | Aug 22, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 22, 2026 | filing ↗ |
| Earnings (2.02) | Aug 10, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 10, 2026 | filing ↗ |
| Shareholder vote (5.07) | Jun 26, 2026 | filing ↗ |
| Earnings (2.02) | May 11, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 11, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Apr 13, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Apr 13, 2026 | filing ↗ |
| Earnings (2.02) | Mar 9, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Mar 9, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Mar 1, 2026 | filing ↗ |
| Other events (8.01) | Mar 1, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Mar 1, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Jan 12, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jan 12, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Jan 8, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jan 8, 2026 | filing ↗ |
| Earnings (2.02) | Nov 10, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Nov 10, 2025 | filing ↗ |
| Officer/director changes (5.02) | Sep 25, 2025 | filing ↗ |
| Reg FD disclosure (7.01) | Sep 25, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Sep 25, 2025 | filing ↗ |