TECX · Tectonic Therapeutic, Inc. · Shareholders & Ownership

$21.71 -0.14 (-0.62%)

Russell 2000 member Rebalance outlook locked

Market Cap

$430.67M

19.55M

Volume · Oct 22 86.49K Avg daily vol (3M) 215.21K

Every disclosed holder of TECX 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 TECX

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)	123	14,006,260	71.65%	Yes
Insiders (Forms 3, 4, 5)	0	0	0.00%	No
13D/G-only blocks	4	6,227,017	31.85%	Yes
Remaining	—	683,911	-3.50%	Negative
Registered funds (N-PORT, not summed)	133	4,580,037	23.43%	No

Shares outstanding: 19,549,366, 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 TECX

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 · Apr 11, 2025 Director, 10% Owner, issuer-wide, not summed	5,838,204	29.86%	—	Apr 11, 2025	Director, 10% Owner, issuer-wide, not summed
1.1	Timothy A. Springer 13D CIK 1055624 · Unknown · Apr 3, 2025	4,313,558	22.07%	+87,500	Apr 3, 2025
2	FMR LLC 13F CIK 315066 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	2,830,378	14.48%	+13,884	Jun 30, 2026	carried, not yet filed for the newest quarter
2.1	Fidelity Growth Company Fund Fund S000007119 · Registered fund · May 31, 2026 Fidelity Mt. Vernon Street Trust, not summed	720,235	3.68%	+20,264	May 31, 2026	Fidelity Mt. Vernon Street Trust, not summed
2.2	Select Biotechnology Portfolio Fund S000007486 · Registered fund · May 31, 2026 Fidelity Select Portfolios, not summed	405,389	2.07%	-37,500	May 31, 2026	Fidelity Select Portfolios, not summed
2.3	Fidelity Growth Company K6 Fund Fund S000065696 · Registered fund · May 31, 2026 Fidelity Mt. Vernon Street Trust, not summed	248,743	1.27%	+2,908	May 31, 2026	Fidelity Mt. Vernon Street Trust, not summed
2.4	Fidelity Series Growth Company Fund Fund S000042626 · Registered fund · May 31, 2026 Fidelity Mt. Vernon Street Trust, not summed	196,522	1.01%	+5,600	May 31, 2026	Fidelity Mt. Vernon Street Trust, not summed
2.5	Fidelity Advisor Biotechnology Fund Fund S000005321 · Registered fund · Jul 31, 2026 Fidelity Advisor Series VII, not summed	120,995	0.62%	0	Jul 31, 2026	Fidelity Advisor Series VII, not summed
3	TCG Crossover Management, LLC 13F CIK 1839948 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	1,204,891	6.16%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
4	TCG Crossover GP II, LLC 13G CIK 1969280 · Unknown · Feb 12, 2026 Rule 13d-1(c), passive investor	1,169,760	5.98%	—	Feb 12, 2026	Rule 13d-1(c), passive investor
5	Aberdeen Group plc 13F CIK 1716774 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	1,141,824	5.84%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
6	BlackRock, Inc. 13F CIK 2012383 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	862,592	4.41%	+2,240	Jun 30, 2026	carried, not yet filed for the newest quarter
6.1	iShares Russell 2000 ETF Fund S000004344 · Registered fund · Jun 30, 2026 iShares Trust, not summed	268,951	1.38%	-1,368	Jun 30, 2026	iShares Trust, not summed
6.2	iShares Russell 2000 Value ETF Fund S000004342 · Registered fund · Jun 30, 2026 iShares Trust, not summed	78,065	0.40%	+1,551	Jun 30, 2026	iShares Trust, not summed
6.3	iShares Biotechnology ETF Fund S000004350 · Registered fund · Jun 30, 2026 iShares Trust, not summed	66,553	0.34%	-9,336	Jun 30, 2026	iShares Trust, not summed
6.4	iShares Micro-Cap ETF Fund S000004439 · Registered fund · Jun 30, 2026 iShares Trust, not summed	34,417	0.18%	+6,721	Jun 30, 2026	iShares Trust, not summed
6.5	iShares Russell 2000 Growth ETF Fund S000004343 · Registered fund · Jun 30, 2026 iShares Trust, not summed	19,539	0.10%	+5,057	Jun 30, 2026	iShares Trust, not summed
7	First Light Asset Management, LLC 13F CIK 1600004 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	800,726	4.10%	+152,983	Jun 30, 2026	carried, not yet filed for the newest quarter
8	MCGUIRE TERRANCE Insider CIK 1117003 · Apr 7, 2025 Director, issuer-wide, not summed	657,976	3.37%	—	Apr 7, 2025	Director, issuer-wide, not summed
8.1	Terrance McGuire 13D CIK 1117003 · Unknown · Apr 3, 2025	657,976	3.37%	-500,001	Apr 3, 2025
9	BAKER BROS. ADVISORS LP 13F CIK 1263508 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	607,788	3.11%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
10	5AM Venture Management, LLC 13F CIK 1799883 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	606,660	3.10%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
11	BRAIDWELL LP 13F CIK 1920938 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	596,900	3.05%	-250,251	Jun 30, 2026	carried, not yet filed for the newest quarter
12	VANGUARD CAPITAL MANAGEMENT LLC 13F CIK 2100119 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	488,805	2.50%	+15,273	Jun 30, 2026	carried, not yet filed for the newest quarter
13	REICIN ALISE Insider CIK 1757533 · Sep 25, 2026 Director, issuer-wide, not summed	436,108	2.23%	-1,545	Sep 25, 2026	Director, issuer-wide, not summed
14	Vestal Point Capital, LP 13F CIK 1974915 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	425,000	2.17%	+97,000	Jun 30, 2026	carried, not yet filed for the newest quarter
15	abrdn Life Sciences Investors Fund · Registered fund · Jun 30, 2026 abrdn Life Sciences Investors, not summed	370,884	1.90%	—	Jun 30, 2026	abrdn Life Sciences Investors, not summed
15.1	abrdn Healthcare Investors Fund · Registered fund · Jun 30, 2026 abrdn Healthcare Investors, not summed	770,940	3.94%	—	Jun 30, 2026	abrdn Healthcare Investors, not summed
15.2	Guggenheim Active Allocation Fund Fund · Registered fund · May 29, 2026 Guggenheim Active Allocation Fund, not summed	18	0.00%	—	May 29, 2026	Guggenheim Active Allocation Fund, not summed
16	VANGUARD TOTAL STOCK MARKET INDEX FUND Fund S000002848 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	364,413	1.86%	+15,000	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
17	Bollard Group LLC 13F CIK 1556218 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	302,953	1.55%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
18	KENNEDY CAPITAL MANAGEMENT LLC 13F CIK 884589 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	282,202	1.44%	-4,480	Jun 30, 2026	carried, not yet filed for the newest quarter
19	GEODE CAPITAL MANAGEMENT, LLC 13F CIK 1214717 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	270,461	1.38%	+2,188	Jun 30, 2026	carried, not yet filed for the newest quarter
20	ORBIMED ADVISORS LLC 13F CIK 1055951 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	226,600	1.16%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
21	STATE STREET CORP 13F CIK 93751 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	219,908	1.12%	+6,403	Jun 30, 2026	carried, not yet filed for the newest quarter
21.1	STATE STREET SMALL/MID CAP EQUITY INDEX PORTFOLIO Fund S000050332 · Registered fund · Jun 30, 2026 STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed	3,900	0.02%	0	Jun 30, 2026	STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed
21.2	State Street Total Return V.I.S. Fund Fund S000001637 · Registered fund · Jun 30, 2026 STATE STREET VARIABLE INSURANCE SERIES FUNDS INC, not summed	279	0.00%	0	Jun 30, 2026	STATE STREET VARIABLE INSURANCE SERIES FUNDS INC, not summed
21.3	State Street Balanced Index Fund Fund S000082802 · Registered fund · Jun 30, 2026 STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed	73	0.00%	0	Jun 30, 2026	STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed
22	Ikarian Capital, LLC 13F CIK 1778253 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	205,837	1.05%	+48,300	Jun 30, 2026	carried, not yet filed for the newest quarter
23	D. E. Shaw & Co., Inc. 13F CIK 1009207 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	186,550	0.95%	+70,430	Jun 30, 2026	carried, not yet filed for the newest quarter
24	MARSHALL WACE, LLP 13F CIK 1318757 · Exempt reporting adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	172,101	0.88%	-57,494	Jun 30, 2026	carried, not yet filed for the newest quarter
25	MILLENNIUM MANAGEMENT LLC 13F CIK 1273087 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	165,525	0.85%	+107,177	Jun 30, 2026	carried, not yet filed for the newest quarter
26	Squarepoint Ops LLC 13F CIK 1642575 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	145,028	0.74%	-19,391	Jun 30, 2026	carried, not yet filed for the newest quarter
27	AMERIPRISE FINANCIAL INC 13F CIK 820027 · Investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	142,448	0.73%	-984	Jun 30, 2026	carried, not yet filed for the newest quarter
27.1	Columbia Variable Portfolio - Small Company Growth Fund Fund S000010658 · Registered fund · Jun 30, 2026 COLUMBIA FUNDS VARIABLE INSURANCE TRUST, not summed	8,302	0.04%	-787	Jun 30, 2026	COLUMBIA FUNDS VARIABLE INSURANCE TRUST, not summed
27.2	Columbia Research Enhanced Small Cap ETF Fund S000095313 · Registered fund · Jun 30, 2026 Columbia ETF Trust I, not summed	11	0.00%	0	Jun 30, 2026	Columbia ETF Trust I, not summed
28	Columbia Small Cap Growth Fund Fund S000012073 · Registered fund · May 31, 2026 COLUMBIA FUNDS SERIES TRUST I, not summed	121,484	0.62%	-3,018	May 31, 2026	COLUMBIA FUNDS SERIES TRUST I, not summed
29	WELLS FARGO & COMPANY/MN 13F CIK 72971 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	117,428	0.60%	+4,764	Jun 30, 2026	carried, not yet filed for the newest quarter
30	NORTHERN TRUST CORP 13F CIK 73124 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	113,904	0.58%	+35,551	Jun 30, 2026	carried, not yet filed for the newest quarter
30.1	Small Cap Value Fund Fund S000001246 · Registered fund · Jun 30, 2026 Northern Funds, not summed	28,408	0.15%	—	Jun 30, 2026	Northern Funds, not summed
30.2	Small Cap Index Fund Fund S000001245 · Registered fund · Jun 30, 2026 Northern Funds, not summed	5,470	0.03%	0	Jun 30, 2026	Northern Funds, not summed
31	VANGUARD EXTENDED MARKET INDEX FUND Fund S000002841 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	111,919	0.57%	+349	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
32	Soleus Capital Management, L.P. 13F CIK 1802630 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	101,684	0.52%	-20,000	Jun 30, 2026	carried, not yet filed for the newest quarter
33	Woodline Partners LP 13F CIK 1784547 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	100,000	0.51%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
34	VANGUARD PORTFOLIO MANAGEMENT LLC 13F CIK 2100121 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	94,414	0.48%	+30,807	Jun 30, 2026	carried, not yet filed for the newest quarter
35	CITADEL ADVISORS LLC 13F CIK 1423053 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	90,393	0.46%	+90,393	Jun 30, 2026	carried, not yet filed for the newest quarter
36	VV Manager II, LLC 13D CIK 1776851 · Jun 20, 2024	85,723	0.44%	—	Jun 20, 2024
37	GOLDMAN SACHS GROUP INC 13F CIK 886982 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	73,924	0.38%	+11,498	Jun 30, 2026	carried, not yet filed for the newest quarter
37.1	Goldman Sachs Small Cap Equity Insights Fund Fund S000009329 · Registered fund · Jul 31, 2026 Goldman Sachs Trust, not summed	10,971	0.06%	—	Jul 31, 2026	Goldman Sachs Trust, not summed
37.2	Goldman Sachs Small Cap Value Insights Fund Fund S000014929 · Registered fund · Jul 31, 2026 Goldman Sachs Trust, not summed	5,529	0.03%	—	Jul 31, 2026	Goldman Sachs Trust, not summed
37.3	Goldman Sachs Variable Insurance Trust Small Cap Equity Insights Fund Fund S000009355 · Registered fund · Jun 30, 2026 Goldman Sachs Variable Insurance Trust, not summed	1,842	0.01%	+298	Jun 30, 2026	Goldman Sachs Variable Insurance Trust, not summed
37.4	Goldman Sachs Absolute Return Tracker Fund Fund S000020314 · Registered fund · Jun 30, 2026 GOLDMAN SACHS TRUST, not summed	1,276	0.01%	+1,267	Jun 30, 2026	GOLDMAN SACHS TRUST, not summed
38	RAYMOND JAMES FINANCIAL INC 13F CIK 720005 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	72,674	0.37%	+8,478	Jun 30, 2026	carried, not yet filed for the newest quarter
39	SECTORAL ASSET MANAGEMENT INC 13F CIK 1274413 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	71,009	0.36%	+51,950	Jun 30, 2026	carried, not yet filed for the newest quarter
40	VANGUARD FIDUCIARY TRUST CO 13F CIK 933478 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	68,394	0.35%	+499	Jun 30, 2026	carried, not yet filed for the newest quarter
41	Ruddy Marcella K. Insider CIK 2023849 · Sep 25, 2026 Director, issuer-wide, not summed	67,157	0.34%	-525	Sep 25, 2026	Director, issuer-wide, not summed
42	JANE STREET GROUP, LLC 13F CIK 1595888 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	65,821	0.34%	+65,821	Jun 30, 2026	carried, not yet filed for the newest quarter
43	MORGAN STANLEY 13F CIK 895421 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	65,373	0.33%	+525	Jun 30, 2026	carried, not yet filed for the newest quarter
44	Connor, Clark & Lunn Investment Management Ltd. 13F CIK 1596800 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	64,940	0.33%	-2,054	Jun 30, 2026	carried, not yet filed for the newest quarter
45	BOOTHBAY FUND MANAGEMENT, LLC 13F CIK 1549230 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	60,771	0.31%	+14,634	Jun 30, 2026	carried, not yet filed for the newest quarter
46	Lochner Daniel Insider CIK 1791187 · Sep 25, 2026 Chief Financial Officer, issuer-wide, not summed	58,024	0.30%	-520	Sep 25, 2026	Chief Financial Officer, issuer-wide, not summed
47	VANGUARD RUSSELL 2000 INDEX FUND Fund S000030003 · Registered fund · May 31, 2026 VANGUARD SCOTTSDALE FUNDS, not summed	56,310	0.29%	+1,872	May 31, 2026	VANGUARD SCOTTSDALE FUNDS, not summed
48	JPMORGAN CHASE & CO 13F CIK 19617 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	55,364	0.28%	-3,506	Jun 30, 2026	carried, not yet filed for the newest quarter
49	McNamara Peter Insider CIK 2023255 · Sep 30, 2026 Chief Scientific Officer, issuer-wide, not summed	54,305	0.28%	-980	Sep 30, 2026	Chief Scientific Officer, issuer-wide, not summed
50	PRICE T ROWE ASSOCIATES INC /MD/ 13F CIK 80255 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	48,001	0.25%	-116,054	Jun 30, 2026	carried, not yet filed for the newest quarter
50.1	T. Rowe Price Health Sciences Fund, Inc. Fund S000002088 · Registered fund · Jun 30, 2026 T. ROWE PRICE HEALTH SCIENCES FUND, INC., not summed	30,632	0.16%	-91,622	Jun 30, 2026	T. ROWE PRICE HEALTH SCIENCES FUND, INC., not summed
50.2	T. Rowe Price Health Sciences Portfolio Fund S000002083 · Registered fund · Jun 30, 2026 T. ROWE PRICE EQUITY SERIES, INC., not summed	2,081	0.01%	-5,519	Jun 30, 2026	T. ROWE PRICE EQUITY SERIES, INC., not summed
50.3	T. Rowe Price Small-Cap Index Fund Fund S000051327 · Registered fund · Jun 30, 2026 T. ROWE PRICE INDEX TRUST, INC., not summed	1,473	0.01%	0	Jun 30, 2026	T. ROWE PRICE INDEX TRUST, INC., not summed

16 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 205 holders

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Key facts CIK 1681087 CUSIP 878972108 13F (30d) 8 filings 8 filers Visit website Investor relations