ICU · SeaStar Medical Holding Corp · Shareholders & Ownership

$2.47 +0.06 (+2.49%) At close · Oct 26

Market Cap

$10.62M

4.41M

Volume · Oct 26 102.69K Avg daily vol (3M) 122.05K

Every disclosed holder of ICU 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.

How the holder list picks a filing →

Who Owns ICU

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

Holder group	Holders	Shares	% Out	Summed
Institutional (13F)	32	1,301,568	29.54%	Yes
Insiders (Forms 3, 4, 5)	0	0	0.00%	No
13D/G-only blocks	3	868,299	19.70%	Yes
Remaining	—	2,236,974	50.76%	Rest
Registered funds (N-PORT, not summed)	6	72,772	1.65%	No

Shares outstanding: 4,406,841, 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.

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 ICU

One row per holder Every filing By ultimate parent

All 13F Funds Insiders 13D/G Non-US

#	Holder	Shares	% Out	Change	As of	Notes
1	Mitchell P. Kopin 13G CIK 1646799 · Unknown · Mar 31, 2026 Rule 13d-1(c), passive investor	443,253	10.06%	+45,186	Mar 31, 2026	Rule 13d-1(c), passive investor
2	Ayrton Capital LLC 13G CIK 1698148 · Registered investment adviser · Mar 31, 2026 Rule 13d-1(b), qualified institution	278,436	6.32%	+249,000	Mar 31, 2026	Rule 13d-1(b), qualified institution
3	BOOTHBAY FUND MANAGEMENT, LLC 13F CIK 1549230 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	245,200	5.56%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
4	Linden Advisors LP 13F CIK 1279396 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	218,073	4.95%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
5	GOLDMAN SACHS GROUP INC 13F CIK 886982 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	211,381	4.80%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
6	ARMISTICE CAPITAL, LLC 13G CIK 1601086 · Registered investment adviser · Jun 30, 2025 Rule 13d-1(b), qualified institution	146,610	3.33%	+44,614	Jun 30, 2025	Rule 13d-1(b), qualified institution
7	LMR Partners LLP 13F CIK 1578621 · Exempt reporting adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	125,000	2.84%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
8	SkyView Investment Advisors, LLC 13F CIK 1848237 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	64,658	1.47%	+64,658	Jun 30, 2026	carried, not yet filed for the newest quarter
9	Schlorff Eric Insider CIK 1949738 · Jul 1, 2026 Chief Executive Officer, issuer-wide, not summed	50,140	1.14%	+10,288	Jul 1, 2026	Chief Executive Officer, issuer-wide, not summed
10	GEODE CAPITAL MANAGEMENT, LLC 13F CIK 1214717 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	49,593	1.13%	-6,049	Jun 30, 2026	carried, not yet filed for the newest quarter
11	Clear Street Group Inc. 13F CIK 1881567 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	46,690	1.06%	+200	Jun 30, 2026	carried, not yet filed for the newest quarter
12	Virtu Financial LLC 13F CIK 1533964 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	40,316	0.91%	+40,316	Jun 30, 2026	carried, not yet filed for the newest quarter
13	TENOR CAPITAL MANAGEMENT Co., L.P. 13F CIK 1346554 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	40,000	0.91%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
14	SUSQUEHANNA INTERNATIONAL GROUP, LLP 13F CIK 1446194 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	36,179	0.82%	+36,179	Jun 30, 2026	carried, not yet filed for the newest quarter
15	EQUITEC PROPRIETARY MARKETS, LLC 13F CIK 1143261 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	35,700	0.81%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
16	VANGUARD CAPITAL MANAGEMENT LLC 13F CIK 2100119 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	33,091	0.75%	+4,300	Jun 30, 2026	carried, not yet filed for the newest quarter
17	VANGUARD EXTENDED MARKET INDEX FUND Fund S000002841 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	33,091	0.75%	+9,208	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
18	Cruiser Capital Advisors, LLC 13F CIK 1713506 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	32,473	0.74%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
19	UBS Group AG 13F CIK 1610520 · Bank · Jun 30, 2026 Classes ICU, ICUCW, carried, not yet filed for the newest quarter	32,199	0.73%	+30,689	Jun 30, 2026	Classes ICU, ICUCW, carried, not yet filed for the newest quarter
20	Chung Kevin Insider CIK 1949950 · Jul 1, 2026 Chief Medical Officer, issuer-wide, not summed	28,021	0.64%	+7,202	Jul 1, 2026	Chief Medical Officer, issuer-wide, not summed
21	TWO SIGMA SECURITIES, LLC 13F CIK 1450144 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	24,322	0.55%	+24,322	Jun 30, 2026	carried, not yet filed for the newest quarter
22	Fidelity Extended Market Index Fund Fund S000006021 · Registered fund · May 31, 2026 Fidelity Concord Street Trust, not summed	21,929	0.50%	-313	May 31, 2026	Fidelity Concord Street Trust, not summed
23	Neuman John Insider CIK 2026279 · Jul 1, 2026 Director, issuer-wide, not summed	16,200	0.37%	+4,000	Jul 1, 2026	Director, issuer-wide, not summed
24	VANGUARD FIDUCIARY TRUST CO 13F CIK 933478 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	13,692	0.31%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
25	JANE STREET GROUP, LLC 13F CIK 1595888 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	12,634	0.29%	-15,326	Jun 30, 2026	carried, not yet filed for the newest quarter
26	Van Heel Kenneth Insider CIK 1613111 · Jul 1, 2026 Director, issuer-wide, not summed	11,940	0.27%	+4,000	Jul 1, 2026	Director, issuer-wide, not summed
27	StoneX Group Inc. 13F CIK 913760 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	11,086	0.25%	+11,086	Jun 30, 2026	carried, not yet filed for the newest quarter
28	WOLVERINE ASSET MANAGEMENT LLC 13F CIK 1279891 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	11,081	0.25%	-1,200	Jun 30, 2026	carried, not yet filed for the newest quarter
29	Baird Jennifer A Insider CIK 2047015 · Jul 1, 2026 Director, issuer-wide, not summed	10,620	0.24%	+4,000	Jul 1, 2026	Director, issuer-wide, not summed
30	NORTHERN TRUST CORP 13F CIK 73124 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	10,402	0.24%	+10,402	Jun 30, 2026	carried, not yet filed for the newest quarter
31	Towne Bradford K Insider CIK 1728197 · Feb 6, 2026 Principal Accounting Officer, issuer-wide, not summed	9,050	0.21%	+7,500	Feb 6, 2026	Principal Accounting Officer, issuer-wide, not summed
32	Fidelity Total Market Index Fund Fund S000006026 · Registered fund · May 31, 2026 Fidelity Concord Street Trust, not summed	8,656	0.20%	+6,441	May 31, 2026	Fidelity Concord Street Trust, not summed
33	Vincent Bernadette N Insider CIK 2047074 · Jul 1, 2026 Director, issuer-wide, not summed	8,200	0.19%	+4,000	Jul 1, 2026	Director, issuer-wide, not summed
34	Fidelity Series Total Market Index Fund Fund S000065248 · Registered fund · May 31, 2026 Fidelity Concord Street Trust, not summed	5,814	0.13%	+1,838	May 31, 2026	Fidelity Concord Street Trust, not summed
35	PNC FINANCIAL SERVICES GROUP, INC. 13F CIK 713676 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	4,943	0.11%	+3,195	Jun 30, 2026	carried, not yet filed for the newest quarter
36	Dimensional U.S. Core Equity 2 ETF Fund S000070903 · Registered fund · Jul 31, 2026 Dimensional ETF Trust, not summed	2,835	0.06%	—	Jul 31, 2026	Dimensional ETF Trust, not summed
37	Messinger Michael Insider CIK 1615039 · Aug 18, 2026 Chief Financial Officer, issuer-wide, not summed	2,500	0.06%	+750	Aug 18, 2026	Chief Financial Officer, issuer-wide, not summed
38	Tower Research Capital LLC (TRC) 13F CIK 1533421 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	1,356	0.03%	-39	Jun 30, 2026	carried, not yet filed for the newest quarter
39	BlackRock, Inc. 13F CIK 2012383 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	913	0.02%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
40	Fidelity Nasdaq Composite Index Fund Fund S000055366 · Registered fund · May 31, 2026 Fidelity Concord Street Trust, not summed	447	0.01%	0	May 31, 2026	Fidelity Concord Street Trust, not summed
41	OSAIC HOLDINGS, INC. 13F CIK 1677044 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	195	0.00%	-35	Jun 30, 2026	carried, not yet filed for the newest quarter
42	NewEdge Advisors, LLC 13F CIK 1633516 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	176	0.00%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
43	Vanguard Global Advisers, LLC 13F CIK 1811242 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	165	0.00%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
44	TD Waterhouse Canada Inc. 13F CIK 1999606 · Unknown · Sep 30, 2026	22	0.00%	0	Sep 30, 2026
45	SBI Securities Co., Ltd. 13F CIK 1851815 · Non-US institution · Sep 30, 2026	14	0.00%	0	Sep 30, 2026
46	SOA Wealth Advisors, LLC. 13F CIK 1849444 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	6	0.00%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
47	BARCLAYS PLC 13F CIK 312069 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	4	0.00%	+4	Jun 30, 2026	carried, not yet filed for the newest quarter
48	Caitong International Asset Management Co., Ltd 13F CIK 1963355 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	2	0.00%	+2	Jun 30, 2026	carried, not yet filed for the newest quarter
49	HighMark Wealth Management LLC 13F CIK 1802451 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	2	0.00%	0	Jun 30, 2026	carried, not yet filed for the newest quarter

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.

Key facts CIK 1831868 CUSIP 81256L302 13F (30d) 2 filings 2 filers Visit website Investor relations