RNAC · Cartesian Therapeutics, Inc. · Shareholders & Ownership

$6.18 -0.23 (-3.59%) At close · Oct 23

Russell 2000 member Rebalance outlook locked

Market Cap

$193.94M

30.26M

Volume · Oct 23 85.9K Avg daily vol (3M) 131.68K

Every disclosed holder of RNAC 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 RNAC

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)	94	8,683,133	28.70%	Yes
Insiders (Forms 3, 4, 5)	17	17,508,110	57.87%	Yes
13D/G-only blocks	2	732,515	2.42%	Yes
Remaining	—	3,331,594	11.01%	Rest
Registered funds (N-PORT, not summed)	81	2,245,132	7.42%	No

Shares outstanding: 30,255,352, the issuer's latest cover-page count restated onto today's split basis.

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 RNAC

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	SPRINGER TIMOTHY A Insider CIK 1055624 · Jan 2, 2026 Director, 10% Owner, issuer-wide	9,633,493	31.84%	+2,600	Jan 2, 2026	Director, 10% Owner, issuer-wide
1.1	Timothy A. Springer 13D CIK 1055624 · Unknown · Jan 13, 2025 not summed	9,555,394	31.58%	+21,178	Jan 13, 2025	not summed
2	Kalayoglu Murat Insider CIK 2000002 · Apr 2, 2026 10% Owner, issuer-wide	5,820,260	19.24%	+753,423	Apr 2, 2026	10% Owner, issuer-wide
2.1	Murat Kalayoglu 13D CIK 2000002 · Unknown · Mar 31, 2026 not summed	5,833,971	19.28%	+2,295,585	Mar 31, 2026	not summed
3	Squarepoint Ops LLC 13F CIK 1642575 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	2,254,619	7.45%	+16,133	Jun 30, 2026	carried, not yet filed for the newest quarter
4	BlackRock, Inc. 13F CIK 2012383 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	819,239	2.71%	+220,131	Jun 30, 2026	carried, not yet filed for the newest quarter
4.1	iShares Russell 2000 ETF Fund S000004344 · Registered fund · Jun 30, 2026 iShares Trust, not summed	338,605	1.12%	+92,281	Jun 30, 2026	iShares Trust, not summed
4.2	iShares Russell 2000 Value ETF Fund S000004342 · Registered fund · Jun 30, 2026 iShares Trust, not summed	94,871	0.31%	+7,890	Jun 30, 2026	iShares Trust, not summed
4.3	iShares Micro-Cap ETF Fund S000004439 · Registered fund · Jun 30, 2026 iShares Trust, not summed	44,124	0.15%	+18,110	Jun 30, 2026	iShares Trust, not summed
4.4	Master Small Cap Index Series Fund S000002716 · Registered fund · Jun 30, 2026 Quantitative Master Series LLC, not summed	29,708	0.10%	+12,152	Jun 30, 2026	Quantitative Master Series LLC, not summed
4.5	iShares Russell 2000 Growth ETF Fund S000004343 · Registered fund · Jun 30, 2026 iShares Trust, not summed	17,053	0.06%	+1,105	Jun 30, 2026	iShares Trust, not summed
5	Singer Michael Insider CIK 2000122 · Mar 13, 2026 Director, issuer-wide	704,446	2.33%	-6,555	Mar 13, 2026	Director, issuer-wide
5.1	Michael Singer 13D CIK 2000122 · Unknown · Apr 8, 2024 not summed	769,744	2.54%	-98,954	Apr 8, 2024	not summed
6	683 Capital Management, LLC 13F CIK 1404574 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	650,000	2.15%	+320,000	Jun 30, 2026	carried, not yet filed for the newest quarter
7	Artal Participations S.a r.l 13G CIK 1218180 · Unknown · Jul 12, 2024 Rule 13d-1(c), passive investor	594,940	1.97%	+246,412	Jul 12, 2024	Rule 13d-1(c), passive investor
8	VANGUARD CAPITAL MANAGEMENT LLC 13F CIK 2100119 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	555,823	1.84%	+148,226	Jun 30, 2026	carried, not yet filed for the newest quarter
9	Hoge Elizabeth Insider CIK 2000987 · Apr 2, 2026 10% Owner, issuer-wide	506,999	1.68%	—	Apr 2, 2026	10% Owner, issuer-wide
10	VANGUARD TOTAL STOCK MARKET INDEX FUND Fund S000002848 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	376,309	1.24%	+95,400	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
11	FMR LLC 13F CIK 315066 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	368,429	1.22%	-431,314	Jun 30, 2026	carried, not yet filed for the newest quarter
11.1	Select Biotechnology Portfolio Fund S000007486 · Registered fund · May 31, 2026 Fidelity Select Portfolios, not summed	366,554	1.21%	0	May 31, 2026	Fidelity Select Portfolios, not summed
11.2	Fidelity Small Cap Index Fund Fund S000033638 · Registered fund · Jul 31, 2026 Fidelity Salem Street Trust, not summed	144,043	0.48%	+40,682	Jul 31, 2026	Fidelity Salem Street Trust, not summed
11.3	Fidelity Extended Market Index Fund Fund S000006021 · Registered fund · May 31, 2026 Fidelity Concord Street Trust, not summed	57,254	0.19%	-1,964	May 31, 2026	Fidelity Concord Street Trust, not summed
11.4	Fidelity Nasdaq Composite Index Fund Fund S000055366 · Registered fund · May 31, 2026 Fidelity Concord Street Trust, not summed	16,604	0.05%	+1,565	May 31, 2026	Fidelity Concord Street Trust, not summed
11.5	Fidelity Series Total Market Index Fund Fund S000065248 · Registered fund · May 31, 2026 Fidelity Concord Street Trust, not summed	16,312	0.05%	+1,557	May 31, 2026	Fidelity Concord Street Trust, not summed
12	GEODE CAPITAL MANAGEMENT, LLC 13F CIK 1214717 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	356,525	1.18%	+92,831	Jun 30, 2026	carried, not yet filed for the newest quarter
13	AQR CAPITAL MANAGEMENT LLC 13F CIK 1167557 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	356,456	1.18%	+272,436	Jun 30, 2026	carried, not yet filed for the newest quarter
14	Brunn Carsten Insider CIK 1760229 · Jan 6, 2026 Director, President and CEO, issuer-wide	323,530	1.07%	-23,766	Jan 6, 2026	Director, President and CEO, issuer-wide
15	MILLENNIUM MANAGEMENT LLC 13F CIK 1273087 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	309,887	1.02%	+25,570	Jun 30, 2026	carried, not yet filed for the newest quarter
16	TWO SIGMA INVESTMENTS, LP 13F CIK 1179392 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	296,293	0.98%	+128,980	Jun 30, 2026	carried, not yet filed for the newest quarter
17	STATE STREET CORP 13F CIK 93751 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	249,212	0.82%	+48,875	Jun 30, 2026	carried, not yet filed for the newest quarter
17.1	STATE STREET SMALL/MID CAP EQUITY INDEX PORTFOLIO Fund S000050332 · Registered fund · Jun 30, 2026 STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed	4,290	0.01%	+1,100	Jun 30, 2026	STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed
17.2	State Street Total Return V.I.S. Fund Fund S000001637 · Registered fund · Jun 30, 2026 STATE STREET VARIABLE INSURANCE SERIES FUNDS INC, not summed	239	0.00%	0	Jun 30, 2026	STATE STREET VARIABLE INSURANCE SERIES FUNDS INC, not summed
17.3	State Street Balanced Index Fund Fund S000082802 · Registered fund · Jun 30, 2026 STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed	89	0.00%	0	Jun 30, 2026	STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed
18	MARSHALL WACE, LLP 13F CIK 1318757 · Exempt reporting adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	232,919	0.77%	-18,196	Jun 30, 2026	carried, not yet filed for the newest quarter
19	UBS Group AG 13F CIK 1610520 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	208,647	0.69%	+71,807	Jun 30, 2026	carried, not yet filed for the newest quarter
20	Jupiter Topco LLC 13F CIK 2146052 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	200,905	0.66%	+200,905	Jun 30, 2026	carried, not yet filed for the newest quarter
20.1	Janus Henderson Small Cap Growth Alpha ETF Fund S000052563 · Registered fund · Jul 31, 2026 Janus Detroit Street Trust, not summed	195,163	0.65%	—	Jul 31, 2026	Janus Detroit Street Trust, not summed
21	VANGUARD EXTENDED MARKET INDEX FUND Fund S000002841 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	169,730	0.56%	+55,455	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
22	Privium Fund Management B.V. 13F CIK 1795097 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	151,675	0.50%	-27,439	Jun 30, 2026	carried, not yet filed for the newest quarter
23	MANGROVE PARTNERS IM, LLC 13G CIK 1535392 · Registered investment adviser · Dec 31, 2023 Rule 13d-1(b), qualified institution	137,575	0.45%	—	Dec 31, 2023	Rule 13d-1(b), qualified institution
24	Davis Blaine Insider CIK 1802188 · Jan 6, 2026 Chief Financial Officer, issuer-wide	121,220	0.40%	-10,591	Jan 6, 2026	Chief Financial Officer, issuer-wide
25	NORTHERN TRUST CORP 13F CIK 73124 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	105,698	0.35%	+13,706	Jun 30, 2026	carried, not yet filed for the newest quarter
25.1	Small Cap Index Fund Fund S000001245 · Registered fund · Jun 30, 2026 Northern Funds, not summed	7,010	0.02%	+322	Jun 30, 2026	Northern Funds, not summed
26	ADAR1 Capital Management, LLC 13F CIK 1940272 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	98,877	0.33%	+98,877	Jun 30, 2026	carried, not yet filed for the newest quarter
27	English Emily Insider CIK 2019791 · Jan 2, 2026 Chief Operations Officer, issuer-wide	94,226	0.31%	+24,000	Jan 2, 2026	Chief Operations Officer, issuer-wide
28	VANGUARD FIDUCIARY TRUST CO 13F CIK 933478 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	91,854	0.30%	+21,558	Jun 30, 2026	carried, not yet filed for the newest quarter
29	VANGUARD PORTFOLIO MANAGEMENT LLC 13F CIK 2100121 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	87,317	0.29%	+26,734	Jun 30, 2026	carried, not yet filed for the newest quarter
30	DIADEMA PARTNERS LP 13F CIK 2026172 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	87,057	0.29%	+87,057	Jun 30, 2026	carried, not yet filed for the newest quarter
31	BANK OF AMERICA CORP /DE/ 13F CIK 70858 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	84,624	0.28%	+84,624	Jun 30, 2026	carried, not yet filed for the newest quarter
32	Walleye Capital LLC 13F CIK 1758720 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	81,828	0.27%	+81,828	Jun 30, 2026	carried, not yet filed for the newest quarter
33	GOLDMAN SACHS GROUP INC 13F CIK 886982 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	80,572	0.27%	+49,645	Jun 30, 2026	carried, not yet filed for the newest quarter
33.1	Goldman Sachs Absolute Return Tracker Fund Fund S000020314 · Registered fund · Jun 30, 2026 GOLDMAN SACHS TRUST, not summed	12,395	0.04%	+4,968	Jun 30, 2026	GOLDMAN SACHS TRUST, not summed
34	Jump Financial, LLC 13F CIK 1831577 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	66,800	0.22%	+66,800	Jun 30, 2026	carried, not yet filed for the newest quarter
35	BNP PARIBAS ARBITRAGE, SA 13F CIK 1166588 · Non-US institution · Jun 30, 2026 carried, not yet filed for the newest quarter	63,977	0.21%	+54,027	Jun 30, 2026	carried, not yet filed for the newest quarter
36	Nuveen, LLC 13F CIK 1871926 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	63,454	0.21%	+26,003	Jun 30, 2026	carried, not yet filed for the newest quarter
36.1	College Retirement Equities Fund - Total Global Stock Account Fund S000005080 · Registered fund · Jun 30, 2026 College Retirement Equities Fund, not summed	22,160	0.07%	—	Jun 30, 2026	College Retirement Equities Fund, not summed
36.2	Nuveen Small Cap Blend Index Fund Fund S000005367 · Registered fund · Jul 31, 2026 TIAA-CREF Funds, not summed	17,320	0.06%	+3,843	Jul 31, 2026	TIAA-CREF Funds, not summed
36.3	Nuveen Equity Index Fund Fund S000005360 · Registered fund · Jul 31, 2026 TIAA-CREF Funds, not summed	11,210	0.04%	0	Jul 31, 2026	TIAA-CREF Funds, not summed
37	Jewell Christopher M Insider CIK 2000226 · Jan 10, 2025 Chief Scientific Officer, issuer-wide	62,490	0.21%	+9,000	Jan 10, 2025	Chief Scientific Officer, issuer-wide
38	Kurtoglu Metin Insider CIK 2000284 · Jan 6, 2025 Chief Technology Officer, issuer-wide	62,258	0.21%	-4,875	Jan 6, 2025	Chief Technology Officer, issuer-wide
39	CM Management, LLC 13F CIK 1841857 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	60,000	0.20%	+60,000	Jun 30, 2026	carried, not yet filed for the newest quarter
40	Miljkovic Milos Insider CIK 2000282 · Jan 6, 2026 Chief Medical Officer, issuer-wide	58,820	0.19%	-3,573	Jan 6, 2026	Chief Medical Officer, issuer-wide
41	BARABE TIMOTHY C Insider CIK 1237409 · Jan 2, 2026 Director, issuer-wide	56,966	0.19%	+2,600	Jan 2, 2026	Director, issuer-wide
42	VANGUARD RUSSELL 2000 INDEX FUND Fund S000030003 · Registered fund · May 31, 2026 VANGUARD SCOTTSDALE FUNDS, not summed	53,464	0.18%	+1,393	May 31, 2026	VANGUARD SCOTTSDALE FUNDS, not summed
43	Point72 Asset Management, L.P. 13F CIK 1603466 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	43,627	0.14%	+43,627	Jun 30, 2026	carried, not yet filed for the newest quarter
44	Trexquant Investment LP 13F CIK 1633445 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	41,046	0.14%	+41,046	Jun 30, 2026	carried, not yet filed for the newest quarter
45	BRIDGEWAY CAPITAL MANAGEMENT, LLC 13F CIK 1107261 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	32,500	0.11%	+7,500	Jun 30, 2026	carried, not yet filed for the newest quarter
45.1	Ultra-Small Company Market Fund Fund S000004424 · Registered fund · Jun 30, 2026 Bridgeway Funds, Inc., not summed	32,500	0.11%	+7,500	Jun 30, 2026	Bridgeway Funds, Inc., not summed
46	CHARLES SCHWAB INVESTMENT MANAGEMENT INC 13F CIK 884546 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	32,168	0.11%	+7,239	Jun 30, 2026	carried, not yet filed for the newest quarter
46.1	Schwab Small-Cap Index Fund Fund S000005912 · Registered fund · Jul 31, 2026 SCHWAB CAPITAL TRUST, not summed	32,118	0.11%	+7,229	Jul 31, 2026	SCHWAB CAPITAL TRUST, not summed
47	Bank of New York Mellon Corp 13F CIK 1390777 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	31,816	0.11%	+5,717	Jun 30, 2026	carried, not yet filed for the newest quarter
48	D. E. Shaw & Co., Inc. 13F CIK 1009207 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	28,651	0.09%	+28,651	Jun 30, 2026	carried, not yet filed for the newest quarter
49	Atlatl Advisers LLC 13F CIK 2023168 · Registered investment adviser · Sep 30, 2026	28,509	0.09%	0	Sep 30, 2026
50	ACADIAN ASSET MANAGEMENT LLC 13F CIK 916542 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	27,746	0.09%	+4,262	Jun 30, 2026	carried, not yet filed for the newest quarter

5 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 165 holders

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Key facts CIK 1453687 CUSIP 816212302 13F (30d) 12 filings 12 filers Visit website Investor relations