SEPN · Insider trading · 13F holders · Congress trades
Septerna, Inc. (SEPN)
Who is buying and selling SEPN: company insiders on SEC Form 4, hedge funds and superinvestors on Form 13F, and members of Congress under the STOCK Act. Every figure links to the filing or page it comes from.
- 13F filers holding
- 12
- Insider buys, 90 days
- $0
- Insider sales, 90 days
- $72.3M
- Congress trades, 12 months
- 0
SEPN at a glance
- Between Aug 1, 2026 and Oct 29, 2026, 4 SEPN insiders filed 6 sales worth $72.3M on SEC Form 4, and no open-market purchases; 5 of the sales were pre-planned under Rule 10b5-1.
- 12 13F filers hold SEPN among their 50 largest positions, worth $706.7M combined, including Peter Kolchinsky and Behzad Aghazadeh. The biggest bets by portfolio weight are Samsara Biocapital, LLC (8.7%), Kalehua Capital Management LLC (4.7%) and Catalio Capital Management, LP (3.4%). In their latest 13Fs, 1 manager opened a new position and 2 added to one.
- No member of Congress has disclosed a trade in SEPN.
- SEPN last closed at $45.23 on Oct 29, 2026.
SEPN insider trading
Between Aug 1, 2026 and Oct 29, 2026, 4 SEPN insiders filed 6 sales worth $72.3M on SEC Form 4, and no open-market purchases; 5 of the sales were pre-planned under Rule 10b5-1.
| Filed | Insider | Role | Trade | Shares | Price | Value | Form 4 |
|---|---|---|---|---|---|---|---|
| Oct 19, 2026 | Bhatt Elizabeth | President and COO | Sale10b5-1 | 4,000 | $37.41 | $150K | SEC |
| Sep 3, 2026 | Long Daniel D. | SVP, Drug Discovery | Sale10b5-1 | 3,333 | $37.83 | $126K | SEC |
| Aug 14, 2026 | Ra Capital Management, L.P. | Director, 10% Owner | Sale | 1,493,000 | $42.50 | $63.5M | SEC |
| Aug 14, 2026 | Third Rock Ventures V, L.P. | 10% Owner | Sale10b5-1 | 147,200 | $50.27 | $7.4M | SEC |
| Aug 13, 2026 | Bhatt Elizabeth | President and COO | Sale10b5-1 | 25,000 | $44.00 | $1.1M | SEC |
| Aug 5, 2026 | Long Daniel D. | SVP, Drug Discovery | Sale10b5-1 | 3,334 | $34.47 | $115K | SEC |
Who owns SEPN? Hedge funds and superinvestors
12 13F filers hold SEPN among their 50 largest positions, worth $706.7M combined, including Peter Kolchinsky and Behzad Aghazadeh. The biggest bets by portfolio weight are Samsara Biocapital, LLC (8.7%), Kalehua Capital Management LLC (4.7%) and Catalio Capital Management, LP (3.4%). In their latest 13Fs, 1 manager opened a new position and 2 added to one.
Superinvestors holding SEPN: Peter Kolchinsky 2.0% · Behzad Aghazadeh 0.4%
| Manager | % of portfolio | Value | Shares | Last quarter | 13F |
|---|---|---|---|---|---|
| Peter KolchinskyHedge fund | 2.0% | $234.3M | 6,995,858 | +0.0% shares | Q2 2026 |
| Driehaus Capital Management LLCHedge fund | 0.9% | $148.5M | 4,433,058 | +0.9% shares | Q2 2026 |
| Samsara Biocapital, LLCHedge fund | 8.7% | $105.5M | 3,149,128 | +0.0% shares | Q2 2026 |
| Siren, L.L.C.Investment manager | 1.3% | $63.6M | 1,900,000 | -5.0% shares | Q2 2026 |
| Behzad AghazadehHedge fund | 0.4% | $44.8M | 1,337,500 | +0.0% shares | Q2 2026 |
| First Light Asset Management, LLCHedge fund | 2.0% | $32.3M | 963,260 | +31.4% shares | Q2 2026 |
| ADAR1 Capital Management, LLCHedge fund | 1.5% | $31.5M | 940,747 | -13.7% shares | Q2 2026 |
| Casdin Capital, LLCHedge fund | 0.9% | $18.5M | 553,268 | +0.0% shares | Q2 2026 |
| Catalio Capital Management, LPHedge fund | 3.4% | $18.0M | 536,152 | +82.1% shares | Q2 2026 |
| Kalehua Capital Management LLCHedge fund | 4.7% | $6.5M | 194,544 | +0.0% shares | Q2 2026 |
| Elmind Capital, LPHedge fund | 0.4% | $1.7M | 49,444 | New | Q2 2026 |
| Sofinnova Investments, Inc.Hedge fund | 0.1% | $1.6M | 47,506 | — | Q2 2026 |
Each manager counts with its latest 13F (Q2 2026: 12). Screen SEPN in the grand portfolio →
SEPN stock trades by members of Congress
No member of Congress has disclosed a trade in SEPN.
SEPN questions and answers
Are insiders buying SEPN stock?
Between Aug 1, 2026 and Oct 29, 2026, 4 SEPN insiders filed 6 sales worth $72.3M on SEC Form 4, and no open-market purchases; 5 of the sales were pre-planned under Rule 10b5-1.
Which hedge funds own SEPN?
12 13F filers hold SEPN among their 50 largest positions, worth $706.7M combined, including Peter Kolchinsky and Behzad Aghazadeh. The biggest bets by portfolio weight are Samsara Biocapital, LLC (8.7%), Kalehua Capital Management LLC (4.7%) and Catalio Capital Management, LP (3.4%). In their latest 13Fs, 1 manager opened a new position and 2 added to one.
Has Congress traded SEPN?
No member of Congress has disclosed a trade in SEPN.
Who is the largest holder of SEPN?
Among 13F filers, Peter Kolchinsky reports the largest SEPN position, $234.3M (6,995,858 shares) in its Q2 2026 13F. The biggest bet by portfolio weight is Samsara Biocapital, LLC's: 8.7% of its portfolio.
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