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SPTX · Seaport Therapeutics, Inc. · Shareholders & Ownership

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$20.83 +0.22 (+1.07%)
Market Cap
$1.15B
Shares
53.53M
Volume · Oct 26 124.69K Avg daily vol (3M) 192.61K

Every disclosed holder of SPTX in one list: 13F institutions, Schedule 13D and 13G filers, insiders (Forms 3, 4 and 5) and registered funds, each from its own latest filing. Holders nest by CIK and SEC reporting links, never by name, and each is summed once.

Who Owns SPTX

13F quarter Sep 30, 2026, combined view: filers that have not filed yet carry their Jun 30, 2026 positions

No chart: the summed disclosures exceed shares outstanding, so they are not parts of one whole.

Holder group Shares % Out
Institutional (13F) 37,476,575 70.01%
Insiders (Forms 3, 4, 5) 0 0.00%
13D/G-only blocks 31,722,179 59.26%
Remaining 15,668,204 -29.27%
Registered funds (N-PORT, not summed) 3,914,865 7.31%

Shares outstanding: 53,530,550, the issuer's latest cover-page count restated onto today's split basis.

Insiders are listed but not summed: the issuer has more than one class of common stock and Forms 3, 4 and 5 report one issuer-wide balance across them.

Remaining is negative: the summed disclosures exceed shares outstanding, as when filings are dated at different times or holders that do not disclose their links count the same shares. It is flagged, not clipped.

13D/G-only counts each filer's latest 13D or 13G that no 13F report of the listing contains, that names no 13F filer and that no counted insider files. Funds are never summed: their shares sit inside their advisers' 13F reports.

Holders of SPTX

# Holder Shares
1
PureTech Health plc
Insider CIK 1782999 · May 4, 2026
10% Owner, issuer-wide, not summed
16,685,013
2
PureTech Health plc
13G CIK 2131815 · Unknown · Jun 30, 2026
Rule 13d-1(d), exempt investor
16,685,013
3
ARCH Venture Fund XII, L.P.
13D CIK 1906837 · Unknown · May 4, 2026
Item 4 purpose: Passive investment
6,294,951
4
ARCH Venture Management, LLC
13F CIK 1274403 · Exempt reporting adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
6,294,951
5
ARCH Venture Partners XII, LLC
Insider CIK 1979548 · May 4, 2026
10% Owner, issuer-wide, not summed
6,294,951
6
GAP Coinvestments CDA, L.P.
Insider CIK 1356474 · May 4, 2026
Director, 10% Owner, issuer-wide, not summed
6,101,582
7
General Atlantic (SP), L.P.
Insider CIK 2133363 · May 4, 2026
Director, 10% Owner, issuer-wide, not summed
6,101,582
8
GENERAL ATLANTIC, L.P.
13F CIK 1017645 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
6,101,582
9
Zohar Daphne
13G CIK 1727388 · Unknown · Jun 30, 2026
Rule 13d-1(d), exempt investor
5,225,497
9.1
Zohar Daphne
Insider CIK 1727388 · Apr 30, 2026
Director, Chief Executive Officer, issuer-wide, not summed
1,194,001
10
Sofinnova Investments, Inc.
13F CIK 1631134 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
3,564,871
11
PAUL STEVEN M
13G CIK 1237564 · Unknown · Jun 30, 2026
Rule 13d-1(d), exempt investor
3,516,718
11.1
PAUL STEVEN M
Insider CIK 1237564 · May 4, 2026
Director, issuer-wide, not summed
863,031
12
HEALY JAMES
Insider CIK 1245624 · May 4, 2026
Director, issuer-wide, not summed
2,731,538
13
GOLDMAN SACHS GROUP INC
13F CIK 886982 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
2,178,642
14
TRV GP VI, LLC
13F CIK 1990716 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
2,061,222
15
CANADA PENSION PLAN INVESTMENT BOARD
13F CIK 1283718 · Non-US institution · Jun 30, 2026
carried, not yet filed for the newest quarter
1,975,791
16
JPMORGAN CHASE & CO
13F CIK 19617 · Bank · Jun 30, 2026
carried, not yet filed for the newest quarter
1,815,845
17
Foresite Capital Management VI LLC
13F CIK 2013341 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
1,779,521
18
PRICE T ROWE ASSOCIATES INC /MD/
13F CIK 80255 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
1,308,604
18.1
T. Rowe Price Health Sciences Fund, Inc.
Fund S000002088 · Registered fund · Jun 30, 2026
T. ROWE PRICE HEALTH SCIENCES FUND, INC., not summed
299,319
18.2
T. Rowe Price Health Sciences Portfolio
Fund S000002083 · Registered fund · Jun 30, 2026
T. ROWE PRICE EQUITY SERIES, INC., not summed
18,421
18.3
T. Rowe Price Extended Equity Market Index Fund
Fund S000002090 · Registered fund · Jun 30, 2026
T. ROWE PRICE INDEX TRUST, INC., not summed
6,378
19
FMR LLC
13F CIK 315066 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
1,185,100
19.1
Fidelity Blue Chip Growth Fund
Fund S000007195 · Registered fund · Jul 31, 2026
Fidelity Securities Fund, not summed
235,900
19.2
Fidelity Growth Company Fund
Fund S000007119 · Registered fund · May 31, 2026
Fidelity Mt. Vernon Street Trust, not summed
224,400
19.3
Fidelity Growth Company K6 Fund
Fund S000065696 · Registered fund · May 31, 2026
Fidelity Mt. Vernon Street Trust, not summed
62,296
19.4
Fidelity Series Growth Company Fund
Fund S000042626 · Registered fund · May 31, 2026
Fidelity Mt. Vernon Street Trust, not summed
55,900
19.5
Fidelity Blue Chip Growth K6 Fund
Fund S000057284 · Registered fund · Jul 31, 2026
Fidelity Securities Fund, not summed
48,109
20
Bellevue Group AG
13F CIK 1674546 · Non-US institution · Jun 30, 2026
carried, not yet filed for the newest quarter
1,100,000
21
Siren, L.L.C.
13F CIK 2005245 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
1,095,316
22
JENNISON ASSOCIATES LLC
13F CIK 53417 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
1,079,669
23
JPMorgan Small Cap Growth Fund
Fund S000003859 · Registered fund · Jun 30, 2026
JPMorgan Trust II, not summed
840,931
24
RA CAPITAL MANAGEMENT, L.P.
13F CIK 1346824 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
700,000
25
VANGUARD CAPITAL MANAGEMENT LLC
13F CIK 2100119 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
599,217
26
Woodline Partners LP
13F CIK 1784547 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
586,345
27
BRAIDWELL LP
13F CIK 1920938 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
500,000
28
PERCEPTIVE ADVISORS LLC
13F CIK 1224962 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
500,000
29
PGIM Jennison Health Sciences Fund
Fund S000004380 · Registered fund · May 29, 2026
Prudential Sector Funds, Inc., not summed
438,754
30
VANGUARD TOTAL STOCK MARKET INDEX FUND
Fund S000002848 · Registered fund · Jun 30, 2026
VANGUARD INDEX FUNDS, not summed
426,371
31
PRINCIPAL FINANCIAL GROUP INC
13F CIK 1126328 · Insurance company · Jun 30, 2026
carried, not yet filed for the newest quarter
414,672
31.1
SmallCap Fund
Fund S000007214 · Registered fund · Jul 31, 2026
Principal Funds, Inc, not summed
181,500
31.2
SmallCap Account
Fund S000007675 · Registered fund · Jun 30, 2026
Principal Variable Contract Funds, Inc, not summed
16,200
32
Aberdeen Group plc
13F CIK 1716774 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
310,355
33
UBS Group AG
13F CIK 1610520 · Bank · Jun 30, 2026
carried, not yet filed for the newest quarter
279,184
34
JPMorgan Small Cap Blend Fund
Fund S000002767 · Registered fund · Jun 30, 2026
JPMorgan Trust I, not summed
271,499
35
BlackRock, Inc.
13F CIK 2012383 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
229,863
36
SEVEN GRAND MANAGERS, LLC
13F CIK 1909126 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
225,000
37
CITADEL ADVISORS LLC
13F CIK 1423053 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
191,144
38
GEODE CAPITAL MANAGEMENT, LLC
13F CIK 1214717 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
175,866
39
Pier Capital, LLC
13F CIK 1310051 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
169,985
40
VANGUARD EXTENDED MARKET INDEX FUND
Fund S000002841 · Registered fund · Jun 30, 2026
VANGUARD INDEX FUNDS, not summed
165,436
41
AMERIPRISE FINANCIAL INC
13F CIK 820027 · Investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
131,788
42
Multi-Manager Small Cap Equity Strategies Fund
Fund S000036206 · Registered fund · May 31, 2026
COLUMBIA FUNDS SERIES TRUST I, not summed
107,880
43
CHARLES SCHWAB INVESTMENT MANAGEMENT INC
13F CIK 884546 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
97,693
43.1
Schwab Total Stock Market Index Fund
Fund S000005913 · Registered fund · Jul 31, 2026
SCHWAB CAPITAL TRUST, not summed
18,093
44
VANGUARD FIDUCIARY TRUST CO
13F CIK 933478 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
87,772
45
Pentwater Capital Management LP
13F CIK 1425851 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
83,000
46
MANUFACTURERS LIFE INSURANCE COMPANY, THE
13F CIK 928047 · Non-US institution · Jun 30, 2026
carried, not yet filed for the newest quarter
82,565
47
Alyeska Investment Group, L.P.
13F CIK 1453072 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
75,000
48
STATE STREET CORP
13F CIK 93751 · Bank · Jun 30, 2026
carried, not yet filed for the newest quarter
66,650
49
abrdn Life Sciences Investors
Fund · Registered fund · Jun 30, 2026
abrdn Life Sciences Investors, not summed
55,039
49.1
abrdn Healthcare Investors
Fund · Registered fund · Jun 30, 2026
abrdn Healthcare Investors, not summed
109,862
49.2
abrdn Healthcare Opportunities Fund
Fund · Registered fund · Jun 30, 2026
abrdn Healthcare Opportunities Fund, not summed
88,659
49.3
abrdn World Healthcare Fund
Fund · Registered fund · Jun 30, 2026
abrdn World Healthcare Fund, not summed
56,795
50
ALPS ADVISORS INC
13F CIK 1376113 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
54,328

2 more nested rows are not shown here; Every filing lists them all.

Shares are restated onto today's split basis. Change compares each row with the same holder's previous filing in the same source; a dash means there is none to compare. Nested 13D/G, insider and fund rows are not summed, since a 13F report already holds them.

Showing 1–50 of 90 holders

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Key facts CIK 2042347 CUSIP 81221K108 13F (30d) 3 filings 3 filers Visit website Investor relations