$SEPN

$44.14 +$2.76 (6.67%) Close

$SEPN Overview Financial Statements SEC Filings Executives News Red Flags Capital Raising Ownership Insider Transactions Congressional Trades

Ownership

13F as of Q2 2026 · 46.7M shares outstanding

Who owns SEPN?

By type of holder

Institutions 100.0% Insiders 0.0% Everyone else 0.0%

Concentration Top 10 holders own 98.1%

Ra Capital Management, L.P. 15.0% · TRV GP V, LLC 13.3%

Institutional ownership

100.0%

+2.0 pts vs last qtr

Institutional holders

153

+29 vs last qtr

Net shares bought

+1.5M

by institutions in Q2 2026

New / sold out

47 / 18

positions opened vs closed

How is ownership changing?

Institutions, last 8 quarters

Biggest buyers in Q2 2026

Jupiter Topco LLC NEW +1.3M
Loomis Sayles & Co L P NEW +624.8K

Biggest sellers in Q2 2026

BVF Inc/il SOLD OUT −1.4M
Janus Henderson Group PLC SOLD OUT −890.8K

Who is planning to sell?

Notices of proposed sale, last 12 months

$89.1M

15 notices from 9 people

Shares covered

1.9M

4.13% of the company

Arranged in advance

15%

of the value is under a 10b5-1 plan

Under a 10b5-1 plan No plan

Largest proposed sellers

RA Capital Healthcare Fund LP Affiliate $36M
RA Capital Nexus Fund III, L.P. Affiliate $36M

Every notice on Red Flags →

A Form 144 is notice of a planned sale, not the sale itself. What insiders actually sold is on Insider Transactions.

Is your stake being diluted?

Diluted share count, FY2023–FY2025

+1932.9%

+350.87% a year

Each share's claim on the business

−95.1%

shrank without buying or selling a share

Spent on buybacks vs paid in stock

— vs $13.2M

over 3 fiscal years

Diluted shares, split-adjusted

Buybacks Stock-based comp

How patient are the owners?

Institutional shares by how long they've been held

5+ years0% 3–5 years0% 1–3 years85% Under 1 year15%

Quarterly turnover

9.5%

of institutional shares changed hands

Top 10 managers, median time held

1.5 years

Super Investors

Investment managers reporting SEPN on Form 13F

Holder	Shares	% of company	Change vs last qtr	Held since	% of their book
RC Ra Capital Management, L.P. 13D · 11.8%	7.0M	14.99%	Unchanged	2024	2.0%
Shares held by quarter Peak holding7.0M (Q4'24) Change over 8 quarters+7.0M Share of the company14.990% Disclosed stake13D · 11.8% Ra Capital Management, L.P.'s full portfolio →
TG TRV GP V, LLC	6.2M	13.32%	Unchanged	2024	41.8%
Shares held by quarter Peak holding6.2M (Q4'24) Change over 8 quarters+6.2M Share of the company13.320% TRV GP V, LLC's full portfolio →

Ra Capital Management, L.P.

13D · 11.8%

7.0M

% of company

14.99%

Change vs last qtr

Unchanged

Held since

2024

TRV GP V, LLC

6.2M

% of company

13.32%

Change vs last qtr

Unchanged

Held since

2024

28 more super investors behind a free account

See every manager holding Septerna, Inc., how their position has changed, and how long they've held it.

Institutional Funds

Mutual funds and ETFs reporting SEPN on Form N-PORT; together they hold 14.6% of the company

Fund	Position value	Shares	% of company	% of the fund	As of
VT Vanguard Total Stock Market Index Fund Vanguard Index Funds	$31.1M	927.7K	1.99%	0.00%	June 30, 2026
PO PRIMECAP Odyssey Aggressive Growth Fund PRIMECAP Odyssey Funds	$28.4M	824.6K	1.77%	0.38%	July 31, 2026

Vanguard Total Stock Market Index Fund

Vanguard Index Funds

Position value

$31.1M

% of company

1.99%

% of the fund

0.00%

As of

June 30, 2026

PRIMECAP Odyssey Aggressive Growth Fund

PRIMECAP Odyssey Funds

Position value

$28.4M

% of company

1.77%

% of the fund

0.38%

As of

July 31, 2026

23 more funds behind a free account

See every fund holding Septerna, Inc. and how much of the fund the position is.

Insiders and 5%+ holders

From Forms 3/4/5 and Schedules 13D/G

Holder	Shares	% of company	Change vs last qtr	8 quarters	Held since	% of their book
PK Peter Kolchinsky 5%+ holder 13D · 11.8%	5.5M	11.84%	—	—	—	—
This holder reports through Schedule 13D/G, not a quarterly 13F. Share of the company11.840% Disclosed stake13D · 11.8% View the 13D/G filing →
RS Rajeev Shah 5%+ holder 13D · 11.8%	5.5M	11.84%	—	—	—	—
This holder reports through Schedule 13D/G, not a quarterly 13F. Share of the company11.840% Disclosed stake13D · 11.8% View the 13D/G filing →

Peter Kolchinsky

5%+ holder13D · 11.8%

5.5M

% of company

11.84%

Change vs last qtr

—

Held since

—

Rajeev Shah

5%+ holder13D · 11.8%

5.5M

% of company

11.84%

Change vs last qtr

—

Held since

—

8 more holders behind a free account

See every insider and 5%+ holder of Septerna, Inc..

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