Septerna, Inc.
Septerna, Inc. (SEPN) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · SEPN · as of Sep 30, 2025
Ownership Breakdown
87
Institutional Holders
▼ 7 vs Q2
$837.97M
Total Inst. Value
▲ $368.34M vs Q2
45.08M
Shares Outstanding
freeFloat 41.88%
44.55M
13F Shares Held
▲ 118,559 vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
SEPN largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
RA CAPITAL MANAGEMENT, L.P. pharmaceutical preparations | 7.00M | 15.84% | 15.84% | $131.59B | Nov 14, 2025 | — held |
TRV GP V, LLC pharmaceutical preparations | 6.22M | 14.07% | 14.07% | $116.92B | Nov 13, 2025 | — held |
DRIEHAUS CAPITAL MANAGEMENT LLC pharmaceutical preparations | 4.92M | 11.14% | 11.14% | $92.54B | Nov 14, 2025 | ▲ 239.5K |
TRV GP VI, LLC pharmaceutical preparations | 4.21M | 9.54% | 9.54% | $79.22B | Nov 13, 2025 | — held |
BVF INC/IL pharmaceutical preparations | 4.02M | 9.09% | 9.09% | $75.54B | Nov 14, 2025 | ▼ 380.3K |
SAMSARA BIOCAPITAL, LLC pharmaceutical preparations | 3.15M | 7.13% | 7.13% | $59.24B | Nov 14, 2025 | — held |
SIREN, L.L.C. pharmaceutical preparations | 2.20M | 4.99% | 4.99% | $41.43B | Nov 13, 2025 | — held |
VANGUARD GROUP INC pharmaceutical preparations | 1.52M | 3.44% | 3.44% | $28.57B | Nov 7, 2025 | ▲ 104.4K |
BLACKROCK, INC. pharmaceutical preparations | 1.46M | 3.31% | 3.31% | $27.46B | Nov 12, 2025 | ▲ 69.0K |
GOLDMAN SACHS GROUP INC pharmaceutical preparations | 1.45M | 3.29% | 3.29% | $27.36B | Nov 14, 2025 | ▲ 38.4K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
19
Increased
+1.70M shares6
New Positions
first time holders13
Decreased
−1.60M shares0
Sold Out
fully exitedNet shares change (top 50)
+101.5K
+1.70M / −1.60M
Net new holders
+12
6 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
SEPN insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
2
Buy transactions
6
Sell transactions
0.33
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Shaikhly Samira Chief People Officer | Jun 1, 2026 | Sale | 1,700 | $27.78 | $47.2K | 5.0K | Form 4 ↗ |
Shaikhly Samira Chief People Officer | Jun 1, 2026 | Sale | 1,346 | $28.79 | $38.8K | 3.7K | Form 4 ↗ |
Shaikhly Samira Chief People Officer | Jun 1, 2026 | Sale | 2,889 | $29.66 | $85.7K | 793 | Form 4 ↗ |
Shaikhly Samira Chief People Officer | May 26, 2026 | Sale | 11,798 | $30.06 | $354.7K | 793 | Form 4 ↗ |
Bhatt Elizabeth President and COO | Apr 15, 2026 | Sale | 2,573 | $23.76 | $61.1K | 175.6K | Form 4 ↗ |
Bhatt Elizabeth President and COO | Apr 15, 2026 | Sale | 1,101 | $25.24 | $27.8K | 174.5K | Form 4 ↗ |
Bhatt Elizabeth President and COO | Apr 15, 2026 | Sale | 326 | $25.86 | $8.4K | 174.2K | Form 4 ↗ |
Shaikhly Samira Chief People Officer | Mar 2, 2026 | Sale | 4,090 | $27.51 | $112.5K | 67.2K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Septerna, Inc. (SEPN) is primarily owned by institutional investors, who hold approximately 98.8% of total shares outstanding. Company insiders own approximately 58.12%, while retail and public investors account for the remaining 0.00%.
The largest institutional shareholder of Septerna, Inc. is RA CAPITAL MANAGEMENT, L.P., holding approximately 7.00 million shares — equal to 15.84% of outstanding shares — as of September 30, 2025.
A total of 87 institutional investors currently hold SEPN stock, with a combined institutional value of approximately $837,968,810 as of the most recent 13F filing period.
Frequently asked questions
SEPN ownershipSepterna, Inc. (SEPN) is primarily owned by institutional investors, who hold approximately 98.8% of shares. The largest shareholder is RA CAPITAL MANAGEMENT, L.P. with a 15.84% stake. Company insiders hold 58.12%. Data sourced from SEC Form 13F as of September 30, 2025.