KRRO · Korro Bio, Inc. · Shareholders & Ownership

$9.29 -0.15 (-1.59%) At close · Oct 21

Russell 2000 member Rebalance outlook locked

Market Cap

$136.80M

14.73M

Volume · Oct 21 116K Avg daily vol (3M) 149.92K

Every disclosed holder of KRRO 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 KRRO

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	Holders	Shares	% Out	Summed
Institutional (13F)	107	14,412,796	97.88%	Yes
Insiders (Forms 3, 4, 5)	16	13,934,144	94.63%	Yes
13D/G-only blocks	8	3,830,905	26.02%	Yes
Remaining	—	17,452,199	-118.52%	Negative
Registered funds (N-PORT, not summed)	92	1,543,105	10.48%	No

Shares outstanding: 14,725,646, the issuer's latest cover-page count restated onto today's split basis.

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 KRRO

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	Lynx1 Capital Management LP Insider CIK 1910456 · Aug 10, 2026 10% Owner, issuer-wide, not summed	1,544,980	10.49%	+6,684	Aug 10, 2026	10% Owner, issuer-wide, not summed
1.1	Lynx1 Capital Management LP 13F CIK 1910456 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	1,538,296	10.45%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
2	Venrock Healthcare Capital Partners III, L.P. 13G CIK 1738048 · Unknown · Mar 10, 2026 Rule 13d-1(c), passive investor	1,488,685	10.11%	—	Mar 10, 2026	Rule 13d-1(c), passive investor
3	New Enterprise Associates 17, L.P. 13D CIK 1768564 · Unknown · Mar 10, 2026 not summed	1,435,487	9.75%	+339,362	Mar 10, 2026	not summed
3.1	New Enterprise Associates 17, L.P. Insider CIK 1768564 · Mar 10, 2026 10% Owner, issuer-wide	1,297,893	8.81%	+207,100	Mar 10, 2026	10% Owner, issuer-wide
4	BASKETT FOREST Insider CIK 1277631 · Mar 10, 2026 10% Owner, issuer-wide	1,297,893	8.81%	+207,100	Mar 10, 2026	10% Owner, issuer-wide
5	Behbahani Ali Insider CIK 1613867 · Mar 10, 2026 Director, 10% Owner, issuer-wide	1,297,893	8.81%	+207,100	Mar 10, 2026	Director, 10% Owner, issuer-wide
6	Chang Carmen Insider CIK 1746342 · Mar 10, 2026 10% Owner, issuer-wide	1,297,893	8.81%	+207,100	Mar 10, 2026	10% Owner, issuer-wide
7	Florence Anthony A. Jr. Insider CIK 1559827 · Mar 10, 2026 10% Owner, issuer-wide	1,297,893	8.81%	+207,100	Mar 10, 2026	10% Owner, issuer-wide
8	Makhzoumi Mohamad Insider CIK 1630226 · Mar 10, 2026 10% Owner, issuer-wide	1,297,893	8.81%	+207,100	Mar 10, 2026	10% Owner, issuer-wide
9	Mathers Edward T Insider CIK 1328625 · Mar 10, 2026 10% Owner, issuer-wide	1,297,893	8.81%	+207,100	Mar 10, 2026	10% Owner, issuer-wide
10	NEA Management Company, LLC 13F CIK 1512848 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	1,297,893	8.81%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
11	SANDELL SCOTT D Insider CIK 1237289 · Mar 10, 2026 10% Owner, issuer-wide	1,297,893	8.81%	+207,100	Mar 10, 2026	10% Owner, issuer-wide
12	Walker Paul Edward Insider CIK 1553150 · Mar 10, 2026 10% Owner, issuer-wide	1,297,893	8.81%	+207,100	Mar 10, 2026	10% Owner, issuer-wide
13	Yang Rick Insider CIK 1851328 · Mar 10, 2026 10% Owner, issuer-wide	1,297,893	8.81%	+207,100	Mar 10, 2026	10% Owner, issuer-wide
14	Venrock Adviser, LLC 13F CIK 1615982 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	1,009,500	6.86%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
15	Atlas Venture Life Science Advisors, LLC 13F CIK 1917529 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	962,884	6.54%	-174,265	Jun 30, 2026	carried, not yet filed for the newest quarter
16	Balyasny Asset Management L.P. 13F CIK 1218710 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	951,783	6.46%	-88,271	Jun 30, 2026	carried, not yet filed for the newest quarter
16.1	Balyasny Asset Management L.P. 13G CIK 1218710 · Registered investment adviser · Jun 30, 2026 Rule 13d-1(b), qualified institution, not summed	951,783	6.46%	-88,271	Jun 30, 2026	Rule 13d-1(b), qualified institution, not summed
17	BlackRock, Inc. 13F CIK 2012383 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	817,621	5.55%	+357,615	Jun 30, 2026	carried, not yet filed for the newest quarter
17.1	BlackRock, Inc. 13G CIK 2012383 · Holding company · Jun 30, 2026 Rule 13d-1(b), qualified institution, not summed	747,546	5.08%	—	Jun 30, 2026	Rule 13d-1(b), qualified institution, not summed
17.2	iShares Russell 2000 ETF Fund S000004344 · Registered fund · Jun 30, 2026 iShares Trust, not summed	262,918	1.79%	+101,999	Jun 30, 2026	iShares Trust, not summed
17.3	iShares Russell 2000 Value ETF Fund S000004342 · Registered fund · Jun 30, 2026 iShares Trust, not summed	78,719	0.53%	+22,933	Jun 30, 2026	iShares Trust, not summed
17.4	iShares Russell 2000 Growth ETF Fund S000004343 · Registered fund · Jun 30, 2026 iShares Trust, not summed	56,704	0.39%	—	Jun 30, 2026	iShares Trust, not summed
17.5	iShares Micro-Cap ETF Fund S000004439 · Registered fund · Jun 30, 2026 iShares Trust, not summed	34,046	0.23%	+17,321	Jun 30, 2026	iShares Trust, not summed
18	FORMELA JEAN FRANCOIS Insider CIK 1030575 · Sep 14, 2026 Director, issuer-wide	773,260	5.25%	-48,690	Sep 14, 2026	Director, issuer-wide
19	Affinity Asset Advisors, LLC 13F CIK 1773195 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	706,904	4.80%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
20	Atlas Venture Fund XI, L.P. 13D CIK 1708269 · Unknown · Jun 24, 2026 Item 4 purpose: not restated by this amendment, the earlier 13D's purpose stands	706,556	4.80%	+687,714	Jun 24, 2026
21	Nantahala Capital Management, LLC 13F CIK 1472322 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	660,036	4.48%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
22	ADAGE CAPITAL PARTNERS GP, L.L.C. 13F CIK 1165408 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	540,968	3.67%	+312,568	Jun 30, 2026	carried, not yet filed for the newest quarter
23	ADAR1 Capital Management, LLC 13F CIK 1940272 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	540,054	3.67%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
24	VANGUARD CAPITAL MANAGEMENT LLC 13F CIK 2100119 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	454,778	3.09%	+143,865	Jun 30, 2026	carried, not yet filed for the newest quarter
25	Driehaus Capital Management LLC 13F CIK 938206 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	450,045	3.06%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
26	TCG Crossover Management, LLC 13F CIK 1839948 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	416,301	2.83%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
27	Artal Participations S.a r.l 13G CIK 1218180 · Unknown · Jul 12, 2024 Rule 13d-1(c), passive investor	413,072	2.81%	+404,700	Jul 12, 2024	Rule 13d-1(c), passive investor
28	Kalehua Capital Management LLC 13F CIK 2106181 · Exempt reporting adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	405,040	2.75%	+295,664	Jun 30, 2026	carried, not yet filed for the newest quarter
29	EVENTIDE ASSET MANAGEMENT, LLC 13G CIK 1442891 · Registered investment adviser · Sep 30, 2024 Rule 13d-1(b), qualified institution	391,166	2.66%	-155,159	Sep 30, 2024	Rule 13d-1(b), qualified institution
30	Siren, L.L.C. 13F CIK 2005245 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	347,718	2.36%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
31	VANGUARD TOTAL STOCK MARKET INDEX FUND Fund S000002848 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	311,262	2.11%	+78,200	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
32	AQR CAPITAL MANAGEMENT LLC 13F CIK 1167557 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	298,974	2.03%	+31,219	Jun 30, 2026	carried, not yet filed for the newest quarter
33	GEODE CAPITAL MANAGEMENT, LLC 13F CIK 1214717 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	296,870	2.02%	+123,227	Jun 30, 2026	carried, not yet filed for the newest quarter
34	Deep Track Capital, LP 13G CIK 1856083 · Investment adviser · Jun 30, 2025 Rule 13d-1(c), passive investor	277,966	1.89%	-572,034	Jun 30, 2025	Rule 13d-1(c), passive investor
35	72 Investment Holdings, LLC 13F CIK 1832749 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	276,831	1.88%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
36	Point72 Asset Management, L.P. 13G CIK 1603466 · Registered investment adviser · Mar 31, 2026 Rule 13d-1(c), passive investor	276,831	1.88%	-540,054	Mar 31, 2026	Rule 13d-1(c), passive investor
37	Cormorant Asset Management, LP 13G CIK 1583977 · Registered investment adviser · Sep 30, 2024 Rule 13d-1(b), qualified institution	265,826	1.81%	-263,344	Sep 30, 2024	Rule 13d-1(b), qualified institution
38	STATE STREET CORP 13F CIK 93751 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	232,587	1.58%	+92,246	Jun 30, 2026	carried, not yet filed for the newest quarter
38.1	STATE STREET SMALL/MID CAP EQUITY INDEX PORTFOLIO Fund S000050332 · Registered fund · Jun 30, 2026 STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed	3,400	0.02%	+1,200	Jun 30, 2026	STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed
38.2	State Street Total Return V.I.S. Fund Fund S000001637 · Registered fund · Jun 30, 2026 STATE STREET VARIABLE INSURANCE SERIES FUNDS INC, not summed	338	0.00%	+93	Jun 30, 2026	STATE STREET VARIABLE INSURANCE SERIES FUNDS INC, not summed
39	VANGUARD PORTFOLIO MANAGEMENT LLC 13F CIK 2100121 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	223,551	1.52%	+74,992	Jun 30, 2026	carried, not yet filed for the newest quarter
40	TWO SIGMA INVESTMENTS, LP 13F CIK 1179392 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	178,071	1.21%	+12,599	Jun 30, 2026	carried, not yet filed for the newest quarter
41	VANGUARD EXTENDED MARKET INDEX FUND Fund S000002841 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	135,396	0.92%	+65,665	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
42	JPMORGAN CHASE & CO 13F CIK 19617 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	124,726	0.85%	+56,226	Jun 30, 2026	carried, not yet filed for the newest quarter
43	MILLENNIUM MANAGEMENT LLC 13F CIK 1273087 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	118,434	0.80%	+54,828	Jun 30, 2026	carried, not yet filed for the newest quarter
44	GOLDMAN SACHS GROUP INC 13F CIK 886982 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	116,983	0.79%	+66,442	Jun 30, 2026	carried, not yet filed for the newest quarter
44.1	Goldman Sachs Absolute Return Tracker Fund Fund S000020314 · Registered fund · Jun 30, 2026 GOLDMAN SACHS TRUST, not summed	4,883	0.03%	-286	Jun 30, 2026	GOLDMAN SACHS TRUST, not summed
45	RENAISSANCE TECHNOLOGIES LLC 13F CIK 1037389 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	110,524	0.75%	-25,703	Jun 30, 2026	carried, not yet filed for the newest quarter
46	VANGUARD STRATEGIC SMALL-CAP EQUITY FUND Fund S000012432 · Registered fund · Jun 30, 2026 VANGUARD HORIZON FUNDS, not summed	106,395	0.72%	+18,055	Jun 30, 2026	VANGUARD HORIZON FUNDS, not summed
47	UBS Group AG 13F CIK 1610520 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	105,453	0.72%	+83,777	Jun 30, 2026	carried, not yet filed for the newest quarter
48	NORTHERN TRUST CORP 13F CIK 73124 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	88,089	0.60%	+30,387	Jun 30, 2026	carried, not yet filed for the newest quarter
48.1	Small Cap Index Fund Fund S000001245 · Registered fund · Jun 30, 2026 Northern Funds, not summed	5,888	0.04%	+1,749	Jun 30, 2026	Northern Funds, not summed
49	VANGUARD FIDUCIARY TRUST CO 13F CIK 933478 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	74,901	0.51%	+33,360	Jun 30, 2026	carried, not yet filed for the newest quarter
50	Aiyar Ram Insider CIK 1997920 · Aug 4, 2026 Director, President and CEO, issuer-wide	73,659	0.50%	-5,802	Aug 4, 2026	Director, President and CEO, issuer-wide

7 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 183 holders

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Key facts CIK 1703647 CUSIP 500946108 13F (30d) 12 filings 12 filers Visit website Investor relations