Comparable stake leader
Third Rock Ventures V, L.P.
SEC ownership of Septerna, Inc.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001984086.
Disclosed value leader
Third Rock Ventures V, L.P.
Comparable rows
50/50
Latest evidence
12 Aug 2026
- Public ticker
- SEPN on Nasdaq
- Parsed ownership sources
-
3/4/5, 13D/G, and 13F
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
Third Rock Ventures V, L.P.
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
Third Rock Ventures V, L.P.
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
12 Aug 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001984086
- Issuer location
- South San Francisco, CA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of Septerna, Inc. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
Third Rock Ventures V, L.P.
Disclosed value leader
Third Rock Ventures V, L.P.
Comparable rows
50/50
Latest evidence
12 Aug 2026
3/4/5
13D/G
13F
Lead comparable stake: 14%
13D/G row: Third Rock Ventures V, L.P.
Showing 1-8 of 50 holder rows.
Quick read
Third Rock Ventures V, L.P. leads the comparable SEC ownership view at 14%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens Third Rock Ventures V, L.P.'s linked filing trail.
Comparable ownership
Top 5
Third Rock Ventures V, L.P.
14%
RA CAPITAL MANAGEMENT, L.P.
12%
DRIEHAUS CAPITAL MANAGEMENT LLC
9.8%
BIOTECHNOLOGY VALUE FUND L P
3.8%
Third Rock Ventures GP V, LP
23%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| Third Rock Ventures V, L.P. |
3/4/5
13D/G
10%+ Owner
|
14%
from 13D/G
|
$469,463,739
13,432,506 shares
mixed-class rows
|
+$7,399,858 | 12 Aug 2026 |
| RA CAPITAL MANAGEMENT, L.P. |
13F
13D/G
3/4/5
Company · Director, 10%+ Owner
|
12%
from 13D/G
|
$234,291,284
6,995,858 shares
|
— | 30 Jun 2026 |
| DRIEHAUS CAPITAL MANAGEMENT LLC |
13D/G
13F
Company
|
9.8%
|
$148,463,112
4,433,058 shares
|
-$7,597,307 | 30 Jun 2026 |
| BIOTECHNOLOGY VALUE FUND L P |
13D/G
BVF PARTNERS L P/IL
|
3.8%
|
$42,813,056
1,720,782 shares
|
-$66,562,509 | 31 Dec 2025 |
| Third Rock Ventures GP V, LP |
3/4/5
10%+ Owner
|
23%
|
$451,021,871
10,280,050 shares
|
+$7,399,858 | 12 Aug 2026 |
| Third Rock Ventures GP VI, L.P. |
3/4/5
10%+ Owner
|
23%
|
$451,021,871
10,280,050 shares
|
+$7,399,858 | 12 Aug 2026 |
| TRV GP V, LLC |
3/4/5
13F
10%+ Owner · Company
|
23%
|
$451,021,871
10,280,050 shares
|
+$7,399,858 | 12 Aug 2026 |
| TRV GP VI, LLC |
3/4/5
13F
10%+ Owner · Company
|
23%
|
$451,021,871
10,280,050 shares
|
+$7,399,858 | 12 Aug 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$277,939,805.
Buys
$44,399,149
Insiders: 6
Sells
$322,338,954
Insiders: 8
Net
-$277,939,805
Shares: -6,740,582
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 883,200
Shares: 7,623,782
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 883,200 | 7,530,030 | $44,399,149 | $319,728,033 | -$275,328,883 |
| 3-6 | 0 | 86,251 | $0 | $2,431,838 | -$2,431,838 |
| 6-9 | 0 | 4,000 | $0 | $115,860 | -$115,860 |
| 9-12 | 0 | 3,501 | $0 | $63,223 | -$63,223 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 27 reporting-owner rows connected to Septerna, Inc.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
27
Largest Forms 3/4/5 holder
Third Rock Ventures VI, L.P.
Net 12M change
-$277,939,806
Latest report
12 Aug 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Third Rock Ventures VI, L.P. | 10%+ Owner | $488,309,201 | +$7,399,858 | +1.5% | Mixed | 12 Aug 2026 |
| Third Rock Ventures V, L.P. | 10%+ Owner | $469,463,739 | +$7,399,858 | +1.6% | Mixed | 12 Aug 2026 |
| Third Rock Ventures GP VI, L.P. | 10%+ Owner | $451,021,871 | +$7,399,858 | +1.7% | Mixed | 12 Aug 2026 |
| Third Rock Ventures GP V, LP | 10%+ Owner | $451,021,871 | +$7,399,858 | +1.7% | Mixed | 12 Aug 2026 |
| TRV GP V, LLC | 10%+ Owner | $451,021,871 | +$7,399,858 | +1.7% | Mixed | 12 Aug 2026 |
| TRV GP VI, LLC | 10%+ Owner | $451,021,871 | +$7,399,858 | +1.7% | Mixed | 12 Aug 2026 |
| Peter Kolchinsky | Director, 10%+ Owner | $30,831,327 | -$63,452,500 | -67% | Filing P/S | 12 Aug 2026 |
| RA CAPITAL MANAGEMENT, L.P. | Director, 10%+ Owner | $30,831,327 | -$63,452,500 | -67% | Filing P/S | 12 Aug 2026 |
| Rajeev M. Shah | Director, 10%+ Owner | $30,831,327 | -$63,452,500 | -67% | Filing P/S | 12 Aug 2026 |
| RA Capital Nexus Fund III, L.P. | Director | $30,831,327 | -$63,452,500 | -67% | Filing P/S | 12 Aug 2026 |
| RA Capital Healthcare Fund LP | Director, 10%+ Owner | $30,831,327 | -$63,452,500 | -67% | Filing P/S | 12 Aug 2026 |
| Elizabeth Bhatt | President and COO | $7,665,196 | -$1,449,178 | -16% | Filing P/S | 11 Aug 2026 |
| Daniel D. Long | SVP, Drug Discovery | $3,343,616 | -$825,253 | -20% | Filing P/S | 03 Aug 2026 |
| Jeffrey Finer | Chief Executive Officer, Director | $2,282,263 | Mixed | 06 Feb 2026 | ||
| Uwe Klein | SVP, Biological Sciences | $1,477,880 | Mixed | 06 Feb 2026 | ||
| Alan Ezekowitz | Director | $813,451 | Filing P/S | 26 Jun 2026 | ||
| Ran Xiao | Interim CFO | $339,704 | Mixed | 24 Oct 2024 | ||
| Gil M. Labrucherie | Chief Financial Officer | $234,000 | Filing P/S | 06 Feb 2026 | ||
| Samira Shaikhly | Chief People Officer | $27,897 | -$2,802,023 | -99% | Filing P/S | 29 Jun 2026 |
| Abraham Bassan | Director | Mixed | 26 Jun 2026 |
Recent insider transactions for Septerna, Inc.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Third Rock Ventures V, L.P. | SEPN | Common Stock | Sale | 2.49% | $7,399,858 | $50.27 | 147,200 | 6,068,532 | 12 Aug 2026 | Direct |
| Third Rock Ventures V, L.P. | SEPN | Common Stock | Sale | 2.49% | $7,399,858 | $50.27 | 147,200 | 6,068,532 | 12 Aug 2026 | Direct |
| Third Rock Ventures V, L.P. | SEPN | Common Stock | Sale | 2.49% | $7,399,858 | $50.27 | 147,200 | 6,068,532 | 12 Aug 2026 | Direct |
| Third Rock Ventures V, L.P. | SEPN | Common Stock | Sale | 2.49% | $7,399,858 | $50.27 | 147,200 | 6,068,532 | 12 Aug 2026 | Direct |
| Third Rock Ventures V, L.P. | SEPN | Common Stock | Sale | 2.49% | $7,399,858 | $50.27 | 147,200 | 6,068,532 | 12 Aug 2026 | Direct |
| Third Rock Ventures V, L.P. | SEPN | Common Stock | Sale | 2.49% | $7,399,858 | $50.27 | 147,200 | 6,068,532 | 12 Aug 2026 | Direct |
| RA CAPITAL MANAGEMENT, L.P. | SEPN | Common Stock | Sale | -67.3% | $63,452,500 | $42.50 | -1,493,000 | 725,443 | 12 Aug 2026 | See footnotes |
| RA CAPITAL MANAGEMENT, L.P. | SEPN | Common Stock | Sale | -67.3% | $63,452,500 | $42.50 | -1,493,000 | 725,443 | 12 Aug 2026 | See footnotes |
| Ra Capital Management, L.P. | SEPN | Common Stock | Sale | -67.3% | $63,452,500 | $42.50 | -1,493,000 | 725,443 | 12 Aug 2026 | See footnotes |
| Ra Capital Management, L.P. | SEPN | Common Stock | Sale | -67.3% | $63,452,500 | $42.50 | -1,493,000 | 725,443 | 12 Aug 2026 | See footnotes |
| Ra Capital Management, L.P. | SEPN | Common Stock | Sale | -67.3% | $63,452,500 | $42.50 | -1,493,000 | 725,443 | 12 Aug 2026 | See footnotes |
| Elizabeth Bhatt | SEPN | Common Stock | Sale | -12.6% | $1,100,000 | $44.00 | -25,000 | 174,209 | 11 Aug 2026 | Direct |
| Elizabeth Bhatt | SEPN | Common Stock | Options Exercise | 14.4% | 25,000 | 199,209 | 11 Aug 2026 | Direct | ||
| Elizabeth Bhatt | SEPN | Stock Option (Right to Buy) | Options Exercise | -28.7% | -25,000 | 62,230 | 11 Aug 2026 | Direct | ||
| Daniel D. Long | SEPN | Common Stock | Sale | -3.34% | $114,920 | $34.47 | -3,334 | 96,412 | 03 Aug 2026 | Direct |
| Daniel D. Long | SEPN | Common Stock | Options Exercise | 3.46% | 3,334 | 99,746 | 03 Aug 2026 | Direct | ||
| Daniel D. Long | SEPN | Stock Option (Right to Buy) | Options Exercise | -38.9% | -3,334 | 5,227 | 03 Aug 2026 | Direct | ||
| Elizabeth Bhatt | SEPN | Common Stock | Sale | -2.24% | $135,974 | $33.99 | -4,000 | 174,209 | 15 Jul 2026 | Direct |
| Elizabeth Bhatt | SEPN | Common Stock | Options Exercise | 2.3% | 4,000 | 178,209 | 15 Jul 2026 | Direct | ||
| Elizabeth Bhatt | SEPN | Stock Option (Right to Buy) | Options Exercise | -4.71% | -4,000 | 80,911 | 15 Jul 2026 | Direct | ||
| Daniel D. Long | SEPN | Common Stock | Sale | -3.34% | $114,528 | $34.36 | -3,333 | 96,412 | 01 Jul 2026 | Direct |
| Daniel D. Long | SEPN | Common Stock | Options Exercise | 3.46% | 3,333 | 99,745 | 01 Jul 2026 | Direct | ||
| Daniel D. Long | SEPN | Stock Option (Right to Buy) | Options Exercise | -32.1% | -3,333 | 7,043 | 01 Jul 2026 | Direct | ||
| Samira Shaikhly | SEPN | Common Stock | Sale | -73.3% | $76,622 | $35.18 | -2,178 | 793 | 29 Jun 2026 | Direct |
| Samira Shaikhly | SEPN | Common Stock | Options Exercise | 274.6% | 2,178 | 2,971 | 29 Jun 2026 | Direct | ||
| Samira Shaikhly | SEPN | Stock Option (Right to Buy) | Options Exercise | -9.45% | -2,178 | 20,865 | 29 Jun 2026 | Direct | ||
| RA CAPITAL MANAGEMENT, L.P. | SEPN | Stock Option (Right to Buy) | Award | 15,000 | 15,000 | 26 Jun 2026 | See Footnotes | |||
| RA CAPITAL MANAGEMENT, L.P. | SEPN | Stock Option (Right to Buy) | Award | 15,000 | 15,000 | 26 Jun 2026 | See Footnotes | |||
| Ra Capital Management, L.P. | SEPN | Stock Option (Right to Buy) | Award | 15,000 | 15,000 | 26 Jun 2026 | See Footnotes | |||
| Ra Capital Management, L.P. | SEPN | Stock Option (Right to Buy) | Award | 15,000 | 15,000 | 26 Jun 2026 | See Footnotes | |||
| Ra Capital Management, L.P. | SEPN | Stock Option (Right to Buy) | Award | 15,000 | 15,000 | 26 Jun 2026 | See Footnotes | |||
| Abraham Bassan | SEPN | Stock Option (Right to Buy) | Award | 15,000 | 15,000 | 26 Jun 2026 | Direct | |||
| Shalini Sharp | SEPN | Stock Option (Right to Buy) | Award | 15,000 | 15,000 | 26 Jun 2026 | Direct | |||
| Bernard Coulie | SEPN | Stock Option (Right to Buy) | Award | 15,000 | 15,000 | 26 Jun 2026 | Direct | |||
| Jeffrey K. Tong | SEPN | Stock Option (Right to Buy) | Award | 15,000 | 15,000 | 26 Jun 2026 | Direct | |||
| Keith Michael Gottesdiener | SEPN | Stock Option (Right to Buy) | Award | 11,260 | 11,260 | 26 Jun 2026 | Direct | |||
| Alan Ezekowitz | SEPN | Stock Option (Right to Buy) | Award | 15,000 | 15,000 | 26 Jun 2026 | Direct | |||
| Jake Simson | SEPN | Stock Option (Right to Buy) | Award | 15,000 | 15,000 | 26 Jun 2026 | Direct | |||
| Daniel D. Long | SEPN | Common Stock | Sale | -13.5% | $532,582 | $35.51 | -15,000 | 96,412 | 22 Jun 2026 | Direct |
| Daniel D. Long | SEPN | Common Stock | Options Exercise | 15.6% | 15,000 | 111,412 | 22 Jun 2026 | Direct | ||
| Daniel D. Long | SEPN | Stock Option (Right to Buy) | Options Exercise | -59.1% | -15,000 | 10,376 | 22 Jun 2026 | Direct | ||
| Samira Shaikhly | SEPN | Common Stock | Sale | -88.7% | $219,224 | $35.08 | -6,250 | 793 | 12 Jun 2026 | Direct |
| Samira Shaikhly | SEPN | Common Stock | Options Exercise | 788.2% | 6,250 | 7,043 | 12 Jun 2026 | Direct | ||
| Samira Shaikhly | SEPN | Stock Option (Right to Buy) | Options Exercise | -20.8% | -6,250 | 23,750 | 12 Jun 2026 | Direct | ||
| Samira Shaikhly | SEPN | Common Stock | Sale | -88.2% | $171,682 | $28.93 | -5,935 | 793 | 01 Jun 2026 | Direct |
| Samira Shaikhly | SEPN | Common Stock | Options Exercise | 748.4% | 5,935 | 6,728 | 01 Jun 2026 | Direct | ||
| Samira Shaikhly | SEPN | Stock Option (Right to Buy) | Options Exercise | -70.2% | -5,935 | 2,517 | 01 Jun 2026 | Direct | ||
| Samira Shaikhly | SEPN | Common Stock | Sale | -93.7% | $354,656 | $30.06 | -11,798 | 793 | 26 May 2026 | Direct |
| Samira Shaikhly | SEPN | Common Stock | Options Exercise | 1487.8% | 11,798 | 12,591 | 26 May 2026 | Direct | ||
| Samira Shaikhly | SEPN | Stock Option (Right to Buy) | Options Exercise | -33.9% | -11,798 | 23,043 | 26 May 2026 | Direct |
* marks a reported price that did not pass the local price check.