$SPTX

$21.55 +$0.72 (3.46%) Live

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

Ownership

13F as of Q2 2026 · 53.5M shares outstanding

Who owns SPTX?

By type of holder

Institutions 70.0% Insiders 30.0% Everyone else 0.0%

Concentration Top 10 holders own 112.1%

Keith Crandell 11.8% · Robert Nelsen 11.8%

Institutional ownership

70.0%

+70.0 pts vs last qtr

Institutional holders

+54 vs last qtr

Net shares bought

+37.5M

by institutions in Q2 2026

New / sold out

54 / 0

positions opened vs closed

How is ownership changing?

Institutions, last 8 quarters

Biggest buyers in Q2 2026

ARCH Venture Management, LLC NEW +6.3M
General Atlantic, L.P. NEW +6.1M

Biggest sellers in Q2 2026

None.

Who is planning to sell?

No insider has filed a notice of proposed sale (Form 144) for Seaport Therapeutics Inc in the last 12 months.

Is your stake being diluted?

There are not yet two fiscal years of reported share counts for Seaport Therapeutics Inc.

How patient are the owners?

Institutional shares by how long they've been held

5+ years0% 3–5 years0% 1–3 years0% Under 1 year100%

Quarterly turnover

—

of institutional shares changed hands

Top 10 managers, median time held

0 quarters

Super Investors

Investment managers reporting SPTX on Form 13F

Holder	Shares	% of company	Change vs last qtr	Held since	% of their book
AV ARCH Venture Management, LLC	6.3M	11.76%	NEW	Q2 '26	12.4%
Shares held by quarter Peak holding6.3M (Q2'26) Change over 8 quarters+6.3M Share of the company11.760% ARCH Venture Management, LLC's full portfolio →
GA General Atlantic, L.P. 13D · 11.5%	6.1M	11.40%	NEW	Q2 '26	4.6%
Shares held by quarter Peak holding6.1M (Q2'26) Change over 8 quarters+6.1M Share of the company11.400% Disclosed stake13D · 11.5% General Atlantic, L.P.'s full portfolio →

ARCH Venture Management, LLC

6.3M

% of company

11.76%

Change vs last qtr

NEW

Held since

Q2 '26

General Atlantic, L.P.

13D · 11.5%

6.1M

% of company

11.40%

Change vs last qtr

NEW

Held since

Q2 '26

23 more super investors behind a free account

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

Institutional Funds

Mutual funds and ETFs reporting SPTX on Form N-PORT; together they hold 8.3% of the company

Fund	Position value	Shares	% of company	% of the fund	As of
JS JPMorgan Small Cap Growth Fund JPMorgan Trust II	$18.3M	840.9K	1.57%	0.70%	June 30, 2026
FG Fidelity Growth Company Fund Fidelity Mt. Vernon Street Trust	$10M	424.2K	0.79%	0.01%	August 31, 2026

JPMorgan Small Cap Growth Fund

JPMorgan Trust II

Position value

$18.3M

% of company

1.57%

% of the fund

0.70%

As of

June 30, 2026

Fidelity Growth Company Fund

Fidelity Mt. Vernon Street Trust

Position value

$10M

% of company

0.79%

% of the fund

0.01%

As of

August 31, 2026

23 more funds behind a free account

See every fund holding Seaport Therapeutics 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
KC Keith Crandell 5%+ holder 13D · 11.9%	6.3M	11.76%	—	—	—	—
This holder reports through Schedule 13D/G, not a quarterly 13F. Share of the company11.760% Disclosed stake13D · 11.9% View the 13D/G filing →
RN Robert Nelsen 5%+ holder 13D · 11.9%	6.3M	11.76%	—	—	—	—
This holder reports through Schedule 13D/G, not a quarterly 13F. Share of the company11.760% Disclosed stake13D · 11.9% View the 13D/G filing →

Keith Crandell

5%+ holder13D · 11.9%

6.3M

% of company

11.76%

Change vs last qtr

—

Held since

—

Robert Nelsen

5%+ holder13D · 11.9%

6.3M

% of company

11.76%

Change vs last qtr

—

Held since

—

14 more holders behind a free account

See every insider and 5%+ holder of Seaport Therapeutics Inc.

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