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Septerna, Inc.

SEPN
Exchange
Nasdaq
Industry
Pharmaceutical Preparations
SEC CIK
0001984086

In the last 90 days, Septerna, Inc. insiders filed 0 open-market purchases and 7 sales; 153 institutions reported holding it in 13F filings for Q2 2026, worth $1.58B in total; no superinvestor holds it.

Holders of 5% or more of SEPN

Holders whose latest Schedule 13D or 13G filing reports 5% or more of Septerna, Inc., largest stake first. The change is against the holder's previous filing.

Holders of 5% or more of SEPN
HolderLatest formStakeChangeFirst filedLatest filingFiling
Third Rock Ventures V, L.P.13G/A14.00%6.22M shares0.00 ppfrom 14.00%Feb 13, 20252 filingsMay 9, 2025SEC
Driehaus Capital Management LLC13G/A10.46%4.66M shares+3.43 ppfrom 7.03%Feb 14, 20253 filingsJun 10, 2025SEC

Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.

13D and 13G filings

7 Schedule 13D and 13G filings on Septerna, Inc., newest first, including old-format filings without a stake.

Schedule 13D and 13G filings on SEPN
Filed (ET)FilerFormStakeChangeEvent dateFiling
Aug 14, 20265:14 PM ETRa Capital Management, L.P.and 3 others13D/A11.80%5.53M shares–Aug 12, 2026SEC
Aug 14, 20267:32 AM ETDriehaus Capital Management LLC13G/A9.83%4.43M shares−0.63 ppfrom 10.46%Jun 30, 2026SEC
Feb 17, 20264:25 PM ETBiotechnology Value Fund L Pand 9 others13G/A3.80%1.72M shares−6.10 ppfrom 9.90%Below 5%Dec 31, 2025SEC
Jun 10, 202510:55 AM ETDriehaus Capital Management LLC13G/A10.46%4.66M shares+3.43 ppfrom 7.03%May 31, 2025SEC
May 15, 20254:37 PM ETBiotechnology Value Fund L Pand 9 others13G/A9.90%4.40M shares–Mar 31, 2025SEC
May 15, 20257:17 AM ETDriehaus Capital Management LLC13G/A7.03%3.12M shares+1.20 ppfrom 5.83%Mar 31, 2025SEC
May 9, 20254:15 PM ETThird Rock Ventures V, L.P.and 5 others13G/A14.00%6.22M shares0.00 ppfrom 14.00%Mar 31, 2025SEC
Feb 14, 20257:48 AM ETDriehaus Capital Management LLC13G5.83%2.59M sharesNewDec 31, 2024SEC
Feb 13, 20254:15 PM ETThird Rock Ventures V, L.P.and 5 others13G14.00%6.22M sharesNewDec 31, 2024SEC

Form 144: proposed insider sales

Notices from officers, directors and other affiliates planning to sell Septerna, Inc. shares.

No Form 144 notices for Septerna, Inc. are on file.