Who owns Tectonic Therapeutic (TECX)
Which tracked institutional funds hold TECX, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See TECX company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
33 tracked funds added or opened TECX while 15 trimmed or exited it between 2026-Q1 and 2026-Q2 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
TECX’s largest tracked holder by dollar value, FMR LLC, sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in TECX divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2026-Q1 and 2026-Q2, across 120 tracked filers holding TECX, 63 increased or opened the position and 54 reduced or closed it; over the same quarter, open-market insider Form 4s were net sales.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in TECX between the 2026-Q1 and 2026-Q2 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 5
- CITADEL ADVISORS LLC$3M
- JANE STREET GROUP, LLC$2M
- Trexquant Investment LP$1M
- Fisher Asset Management, LLC$657K
- Quadrature Capital Ltd$621K
Full exits 5
- Bollard Group LLC$9M
- Opaleye Management Inc.$4M
- Point72 Asset Management, L.P.$2M
- TD Asset Management Inc$631K
- GSA CAPITAL PARTNERS LLP$583K
Largest adds
- FMR LLC$10M
- First Light Asset Management, LLC$8M
- Vestal Point Capital, LP$4M
- TCG Crossover Management, LLC$4M
- Aberdeen Group plc$4M
- MILLENNIUM MANAGEMENT LLC$4M
Largest trims
- BRAIDWELL LP$6M
- PRICE T ROWE ASSOCIATES INC /MD/$3M
- ExodusPoint Capital Management, LP$1M
- MARSHALL WACE, LLP$1M
- Prosight Management, LP$1M
- SEI INVESTMENTS CO$554K
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| FMR LLC added | 2,830,378 | $97M | 20.8% | 2026-Q2 |
| TCG Crossover Management, LLC | 1,204,891 | $41M | 8.9% | 2026-Q2 |
| Aberdeen Group plc | 1,141,824 | $39M | 8.4% | 2026-Q2 |
| BlackRock, Inc. added | 862,592 | $30M | 6.3% | 2026-Q2 |
| First Light Asset Management, LLC added | 800,726 | $28M | 5.9% | 2026-Q2 |
| BAKER BROS. ADVISORS LP | 607,788 | $21M | 4.5% | 2026-Q2 |
| 5AM Venture Management, LLC | 606,660 | $21M | 4.5% | 2026-Q2 |
| BRAIDWELL LP trimmed | 596,900 | $21M | 4.4% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 488,805 | $17M | 3.6% | 2026-Q2 |
| Vestal Point Capital, LP added | 425,000 | $15M | 3.1% | 2026-Q2 |
| KENNEDY CAPITAL MANAGEMENT LLC trimmed | 282,202 | $10M | 2.1% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 270,461 | $9M | 2.0% | 2026-Q2 |
| ORBIMED ADVISORS LLC | 226,600 | $8M | 1.7% | 2026-Q2 |
| STATE STREET CORP added | 219,908 | $8M | 1.6% | 2026-Q2 |
| Ikarian Capital, LLC added | 205,837 | $7M | 1.5% | 2026-Q2 |
| D. E. Shaw & Co., Inc. added | 186,550 | $6M | 1.4% | 2026-Q2 |
| MARSHALL WACE, LLP trimmed | 172,101 | $6M | 1.3% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC added | 165,525 | $6M | 1.2% | 2026-Q2 |
| Squarepoint Ops LLC trimmed | 145,028 | $5M | 1.1% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC trimmed | 142,448 | $5M | 1.0% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 117,428 | $4M | 0.9% | 2026-Q2 |
| NORTHERN TRUST CORP added | 113,904 | $4M | 0.8% | 2026-Q2 |
| Soleus Capital Management, L.P. trimmed | 101,684 | $3M | 0.7% | 2026-Q2 |
| Woodline Partners LP | 100,000 | $3M | 0.7% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC added | 94,414 | $3M | 0.7% | 2026-Q2 |
| CITADEL ADVISORS LLC trimmed | 90,393 | $3M | 0.7% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC added | 73,924 | $3M | 0.5% | 2026-Q2 |
| RAYMOND JAMES FINANCIAL INC added | 72,674 | $2M | 0.5% | 2026-Q2 |
| SECTORAL ASSET MANAGEMENT INC added | 71,009 | $2M | 0.5% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 68,394 | $2M | 0.5% | 2026-Q2 |
| JANE STREET GROUP, LLC added | 65,821 | $2M | 0.5% | 2026-Q2 |
| MORGAN STANLEY added | 65,373 | $2M | 0.5% | 2026-Q2 |
| Connor, Clark & Lunn Investment Management Ltd. trimmed | 64,940 | $2M | 0.5% | 2026-Q2 |
| BOOTHBAY FUND MANAGEMENT, LLC added | 60,771 | $2M | 0.4% | 2026-Q2 |
| JPMORGAN CHASE & CO trimmed | 55,364 | $2M | 0.4% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ trimmed | 48,001 | $2M | 0.4% | 2026-Q2 |
| Tetragon Partners GP Ltd added | 46,516 | $2M | 0.3% | 2026-Q2 |
| PFM Health Sciences, LP trimmed | 45,631 | $2M | 0.3% | 2026-Q2 |
| Jump Financial, LLC added | 43,400 | $1M | 0.3% | 2026-Q2 |
| Prosight Management, LP trimmed | 39,731 | $1M | 0.3% | 2026-Q2 |
| Trexquant Investment LP added | 36,991 | $1M | 0.3% | 2026-Q2 |
| Aldebaran Capital, LLC trimmed | 36,797 | $1M | 0.3% | 2026-Q2 |
| ExodusPoint Capital Management, LP trimmed | 35,239 | $1M | 0.3% | 2026-Q2 |
| WELLINGTON MANAGEMENT GROUP LLP added | 31,432 | $1M | 0.2% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 30,438 | $1M | 0.2% | 2026-Q2 |
| MONIMUS CAPITAL MANAGEMENT, LP added | 28,143 | $967K | 0.2% | 2026-Q2 |
| Bank of New York Mellon Corp added | 25,247 | $868K | 0.2% | 2026-Q2 |
| ALPS ADVISORS INC added | 19,147 | $658K | 0.1% | 2026-Q2 |
| Fisher Asset Management, LLC new | 19,122 | $657K | 0.1% | 2026-Q2 |
| AMERICAN CENTURY COMPANIES INC added | 19,001 | $653K | 0.1% | 2026-Q2 |
| Quadrature Capital Ltd added | 18,067 | $621K | 0.1% | 2026-Q2 |
| SEI INVESTMENTS CO trimmed | 17,029 | $585K | 0.1% | 2026-Q2 |
| Clearstead Advisors, LLC trimmed | 16,630 | $572K | 0.1% | 2026-Q2 |
| UBS Group AG trimmed | 15,055 | $518K | 0.1% | 2026-Q2 |
| ADAR1 Capital Management, LLC added | 14,501 | $498K | 0.1% | 2026-Q2 |
| RHUMBLINE ADVISERS trimmed | 13,773 | $473K | 0.1% | 2026-Q2 |
| Nuveen, LLC added | 13,514 | $465K | 0.1% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ trimmed | 11,043 | $380K | 0.1% | 2026-Q2 |
| Virtus Investment Advisers, LLC trimmed | 10,806 | $371K | 0.1% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 10,443 | $359K | 0.1% | 2026-Q2 |
| DEUTSCHE BANK AG\ added | 10,039 | $345K | 0.1% | 2026-Q2 |
| Brevan Howard Capital Management LP new | 9,573 | $329K | 0.1% | 2026-Q2 |
| BARCLAYS PLC added | 9,128 | $314K | 0.1% | 2026-Q2 |
| Creative Planning trimmed | 8,961 | $308K | 0.1% | 2026-Q2 |
| FOX RUN MANAGEMENT, L.L.C. new | 8,865 | $305K | 0.1% | 2026-Q2 |
| Vanguard Global Advisers, LLC added | 8,765 | $301K | 0.1% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. new | 7,460 | $231K | 0.0% | 2026-Q2 |
| AlphaCentric Advisors LLC added | 6,948 | $239K | 0.1% | 2026-Q2 |
| MetLife Investment Management, LLC | 6,724 | $231K | 0.0% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC trimmed | 6,617 | $227K | 0.0% | 2026-Q2 |
| Invesco Ltd. trimmed | 6,388 | $220K | 0.0% | 2026-Q2 |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM new | 6,060 | $208K | 0.0% | 2026-Q2 |
| Velan Capital Investment Management LP new | 6,000 | $206K | 0.0% | 2026-Q2 |
| Rangeley Capital, LLC trimmed | 6,000 | $206K | 0.0% | 2026-Q2 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE trimmed | 5,996 | $206K | 0.0% | 2026-Q2 |
| Russell Investments Group, Ltd. added | 5,567 | $191K | 0.0% | 2026-Q2 |
| CITIGROUP INC added | 5,548 | $191K | 0.0% | 2026-Q2 |
| China Universal Asset Management Co., Ltd. trimmed | 5,503 | $189K | 0.0% | 2026-Q2 |
| NISA INVESTMENT ADVISORS, LLC added | 5,400 | $186K | 0.0% | 2026-Q2 |
| BNP PARIBAS FINANCIAL MARKETS added | 5,146 | $177K | 0.0% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. trimmed | 4,694 | $161K | 0.0% | 2026-Q2 |
| NEW YORK STATE COMMON RETIREMENT FUND | 4,600 | $158K | 0.0% | 2026-Q2 |
| Police & Firemen's Retirement System of New Jersey | 2,638 | $91K | 0.0% | 2026-Q2 |
| Quantbot Technologies LP new | 1,819 | $63K | 0.0% | 2026-Q2 |
| Ameritas Investment Partners, Inc. | 1,122 | $39K | 0.0% | 2026-Q2 |
| US BANCORP \DE\ trimmed | 1,080 | $37K | 0.0% | 2026-Q2 |
| Legal & General Group Plc | 1,000 | $34K | 0.0% | 2026-Q2 |
| Mirae Asset Global Investments Co., Ltd. trimmed | 844 | $29K | 0.0% | 2026-Q2 |
| Chung Wu Investment Group, LLC new | 800 | $28K | 0.0% | 2026-Q2 |
| Arax Advisory Partners added | 725 | $25K | 0.0% | 2026-Q2 |
| Tower Research Capital LLC (TRC) trimmed | 661 | $23K | 0.0% | 2026-Q2 |
| State of Wyoming new | 601 | $21K | 0.0% | 2026-Q2 |
| HighMark Wealth Management LLC | 587 | $20K | 0.0% | 2026-Q2 |
| SIMPLEX TRADING, LLC trimmed | 439 | $15K | 0.0% | 2026-Q2 |
| GF FUND MANAGEMENT CO. LTD. trimmed | 400 | $14K | 0.0% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | 382 | $13K | 0.0% | 2026-Q2 |
| Rockefeller Capital Management L.P. | 370 | $13K | 0.0% | 2026-Q2 |
| ROYAL BANK OF CANADA trimmed | 311 | $11K | 0.0% | 2026-Q2 |
| GAMMA Investing LLC trimmed | 290 | $10K | 0.0% | 2026-Q2 |
| Federation des caisses Desjardins du Quebec trimmed | 250 | $9K | 0.0% | 2026-Q2 |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.