ACET · Adicet Bio, Inc. · Shareholders & Ownership

$4.52 -0.01 (-0.22%) At close · Oct 20

Market Cap

$43.34M

9.36M

Volume · Oct 20 126.54K Avg daily vol (3M) 186.43K

Every disclosed holder of ACET 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 ACET

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)	56	6,108,855	65.26%	Yes
Insiders (Forms 3, 4, 5)	9	32,891	0.35%	Yes
13D/G-only blocks	4	810,452	8.66%	Yes
Remaining	—	2,409,292	25.74%	Rest
Registered funds (N-PORT, not summed)	15	792,510	8.47%	No

Shares outstanding: 9,361,490, 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 ACET

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	RA CAPITAL MANAGEMENT, L.P. 13F CIK 1346824 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	932,624	9.96%	-250,000	Jun 30, 2026	carried, not yet filed for the newest quarter
1.1	RA CAPITAL MANAGEMENT, L.P. 13G CIK 1346824 · Registered investment adviser · Jun 30, 2026 Rule 13d-1(c), passive investor, not summed	935,486	9.99%	-247,138	Jun 30, 2026	Rule 13d-1(c), passive investor, not summed
1.2	RA CAPITAL MANAGEMENT, L.P. Insider CIK 1346824 · Apr 27, 2026 Director, issuer-wide, not summed	932,624	9.96%	-250,000	Apr 27, 2026	Director, issuer-wide, not summed
2	ORBIMED ADVISORS LLC 13F CIK 1055951 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	844,787	9.02%	-183,157	Jun 30, 2026	carried, not yet filed for the newest quarter
2.1	ORBIMED ADVISORS LLC Insider CIK 1055951 · Apr 8, 2026 10% Owner, issuer-wide, not summed	923,286	9.86%	-104,660	Apr 8, 2026	10% Owner, issuer-wide, not summed
3	FRANKLIN RESOURCES INC 13F CIK 38777 · Investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	626,571	6.69%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
3.1	Franklin Biotechnology Discovery Fund Fund S000006882 · Registered fund · Jul 31, 2026 Franklin Strategic Series, not summed	225,186	2.41%	0	Jul 31, 2026	Franklin Strategic Series, not summed
4	CITADEL ADVISORS LLC 13F CIK 1423053 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	432,738	4.62%	+50,915	Jun 30, 2026	carried, not yet filed for the newest quarter
5	TANG CAPITAL MANAGEMENT, LLC 13G CIK 1191935 · Unknown · Dec 31, 2023 Rule 13d-1(c), passive investor	368,750	3.94%	—	Dec 31, 2023	Rule 13d-1(c), passive investor
6	VANGUARD CAPITAL MANAGEMENT LLC 13F CIK 2100119 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	343,228	3.67%	+6,704	Jun 30, 2026	carried, not yet filed for the newest quarter
7	Woodline Partners LP 13G CIK 1784547 · Registered investment adviser · Mar 31, 2026 Rule 13d-1(b), qualified institution	313,124	3.34%	-311,876	Mar 31, 2026	Rule 13d-1(b), qualified institution
8	ADAGE CAPITAL PARTNERS GP, L.L.C. 13F CIK 1165408 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	274,375	2.93%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
9	RENAISSANCE TECHNOLOGIES LLC 13F CIK 1037389 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	265,945	2.84%	+33,354	Jun 30, 2026	carried, not yet filed for the newest quarter
10	Stonepine Capital Management, LLC 13F CIK 1440771 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	245,518	2.62%	+23,563	Jun 30, 2026	carried, not yet filed for the newest quarter
11	VANGUARD TOTAL STOCK MARKET INDEX FUND Fund S000002848 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	240,946	2.57%	+27,828	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
12	Alyeska Investment Group, L.P. 13F CIK 1453072 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	203,799	2.18%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
13	Schonfeld Strategic Advisors LLC 13F CIK 1665241 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	195,514	2.09%	+195,514	Jun 30, 2026	carried, not yet filed for the newest quarter
14	Carlyle Group Inc. 13F CIK 1527166 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	184,295	1.97%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
15	NEXTBio Capital Management LP 13F CIK 2038158 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	157,827	1.69%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
16	ACADIAN ASSET MANAGEMENT LLC 13F CIK 916542 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	124,832	1.33%	+6,694	Jun 30, 2026	carried, not yet filed for the newest quarter
17	MILLENNIUM MANAGEMENT LLC 13G CIK 1273087 · Registered investment adviser · Sep 30, 2024 Rule 13d-1(c), passive investor	122,420	1.31%	-124,214	Sep 30, 2024	Rule 13d-1(c), passive investor
18	VANGUARD EXTENDED MARKET INDEX FUND Fund S000002841 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	98,912	1.06%	-336	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
19	TWO SIGMA INVESTMENTS, LP 13F CIK 1179392 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	96,839	1.03%	+53,733	Jun 30, 2026	carried, not yet filed for the newest quarter
20	GEODE CAPITAL MANAGEMENT, LLC 13F CIK 1214717 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	95,634	1.02%	-5,501	Jun 30, 2026	carried, not yet filed for the newest quarter
21	DAFNA Capital Management LLC 13F CIK 1389933 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	93,812	1.00%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
22	BRIDGEWAY CAPITAL MANAGEMENT, LLC 13F CIK 1107261 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	85,959	0.92%	+85,959	Jun 30, 2026	carried, not yet filed for the newest quarter
22.1	Ultra-Small Company Fund Fund S000004423 · Registered fund · Jun 30, 2026 Bridgeway Funds, Inc., not summed	85,959	0.92%	—	Jun 30, 2026	Bridgeway Funds, Inc., not summed
23	MARSHALL WACE, LLP 13F CIK 1318757 · Exempt reporting adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	79,488	0.85%	+79,488	Jun 30, 2026	carried, not yet filed for the newest quarter
24	Trexquant Investment LP 13F CIK 1633445 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	78,002	0.83%	+34,336	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	70,561	0.75%	+33,477	Jun 30, 2026	carried, not yet filed for the newest quarter
26	Burkehill Global Management, LP 13F CIK 1904549 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	62,500	0.67%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
27	BlackRock, Inc. 13F CIK 2012383 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	62,126	0.66%	+25,541	Jun 30, 2026	carried, not yet filed for the newest quarter
27.1	iShares Micro-Cap ETF Fund S000004439 · Registered fund · Jun 30, 2026 iShares Trust, not summed	23,940	0.26%	—	Jun 30, 2026	iShares Trust, not summed
28	REGENERON PHARMACEUTICALS, INC. 13F CIK 872589 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	60,511	0.65%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
29	Rangeley Capital, LLC 13F CIK 1517796 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	50,892	0.54%	-5,108	Jun 30, 2026	carried, not yet filed for the newest quarter
30	VANGUARD FIDUCIARY TRUST CO 13F CIK 933478 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	50,670	0.54%	+336	Jun 30, 2026	carried, not yet filed for the newest quarter
31	RBF Capital, LLC 13F CIK 1134621 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	38,582	0.41%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
32	STATE STREET CORP 13F CIK 93751 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	36,222	0.39%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
33	Quadrature Capital Ltd 13F CIK 1651424 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	36,193	0.39%	+36,193	Jun 30, 2026	carried, not yet filed for the newest quarter
34	DIMENSIONAL FUND ADVISORS LP 13F CIK 354204 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	31,603	0.34%	+20,825	Jun 30, 2026	carried, not yet filed for the newest quarter
34.1	Dimensional U.S. Small Cap ETF Fund S000070906 · Registered fund · Jul 31, 2026 Dimensional ETF Trust, not summed	14,520	0.16%	+5,148	Jul 31, 2026	Dimensional ETF Trust, not summed
34.2	U.S. MICRO CAP PORTFOLIO Fund S000000948 · Registered fund · Jul 31, 2026 DFA INVESTMENT DIMENSIONS GROUP INC, not summed	14,264	0.15%	+9,394	Jul 31, 2026	DFA INVESTMENT DIMENSIONS GROUP INC, not summed
35	UBS Group AG 13F CIK 1610520 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	29,817	0.32%	-8,551	Jun 30, 2026	carried, not yet filed for the newest quarter
36	Verdad Advisers, LP 13F CIK 1812822 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	25,200	0.27%	+25,200	Jun 30, 2026	carried, not yet filed for the newest quarter
37	XTX Topco Ltd 13F CIK 1828301 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	24,284	0.26%	+5,158	Jun 30, 2026	carried, not yet filed for the newest quarter
38	JOHNSON & JOHNSON 13F CIK 200406 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	22,779	0.24%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
39	SUSQUEHANNA INTERNATIONAL GROUP, LLP 13F CIK 1446194 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	20,650	0.22%	+20,650	Jun 30, 2026	carried, not yet filed for the newest quarter
40	PRELUDE CAPITAL MANAGEMENT, LLC 13F CIK 1387508 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	18,550	0.20%	+18,550	Jun 30, 2026	carried, not yet filed for the newest quarter
41	NORTHERN TRUST CORP 13F CIK 73124 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	18,436	0.20%	-764	Jun 30, 2026	carried, not yet filed for the newest quarter
42	OCCUDO QUANTITATIVE STRATEGIES LP 13F CIK 1819697 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	16,636	0.18%	+1,536	Jun 30, 2026	carried, not yet filed for the newest quarter
43	Squarepoint Ops LLC 13F CIK 1642575 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	15,254	0.16%	+15,254	Jun 30, 2026	carried, not yet filed for the newest quarter
44	Vontobel Holding Ltd. 13F CIK 1588340 · Unknown · Sep 30, 2026	12,775	0.14%	-1,001	Sep 30, 2026
45	AXQ CAPITAL, LP 13F CIK 1916908 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	10,991	0.12%	+10,991	Jun 30, 2026	carried, not yet filed for the newest quarter
46	Jump Financial, LLC 13F CIK 1831577 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	10,942	0.12%	+10,942	Jun 30, 2026	carried, not yet filed for the newest quarter
47	Schor Chen Insider CIK 1340875 · Jan 24, 2026 Director, President & CEO, issuer-wide	10,159	0.11%	—	Jan 24, 2026	Director, President & CEO, issuer-wide
48	Klickstein Lloyd Insider CIK 1776004 · Jun 11, 2025 Director, issuer-wide	6,785	0.07%	+368	Jun 11, 2025	Director, issuer-wide
49	TANG CAPITAL MANAGEMENT LLC 13G CIK 1232621 · Unknown · Dec 31, 2025 Rule 13d-1(c), passive investor	6,158	0.07%	-507,818	Dec 31, 2025	Rule 13d-1(c), passive investor
50	Arax Advisory Partners 13F CIK 1586767 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	6,000	0.06%	+6,000	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.

Showing 1–50 of 75 holders

Create a free account to page through every holder, filter by source and group by ultimate parent.

Key facts CIK 1720580 CUSIP 007002207 13F (30d) 3 filings 3 filers Visit website Investor relations