TECTONIC THERAPEUTIC INC TECX
COM · Common Stock · CUSIP 878972108
- SectorHealth care
- IndustryBiological Products, (No Diagnostic Substances)
- HeadquartersWatertown, MA
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($67.1k this quarter). Holder counts are more reliable. Shares outstanding: 19.5m as of 2026-07-31, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $34.37. Options: 4 managers hold calls ($7.0m notional), 2 hold puts ($440.1k).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q2 2024 | 40 |
| Q3 2024 | 54 |
| Q4 2024 | 71 |
| Q1 2025 | 79 |
| Q2 2025 | 83 |
| Q3 2025 | 99 |
| Q4 2025 | 105 |
| Q1 2026 | 111 |
| Q2 2026 | 123 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 29 | 13 |
| Q4 2024 | 43 | 23 |
| Q1 2025 | 58 | 34 |
| Q2 2025 | 52 | 27 |
| Q3 2025 | 58 | 31 |
| Q4 2025 | 63 | 46 |
| Q1 2026 | 58 | 57 |
| Q2 2026 | 64 | 51 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $4.0m | $827.4k | 0.21 |
| Q4 2025 | $9.9m | $1.1m | 0.11 |
| Q1 2026 | $13.5m | $911.8k | 0.07 |
| Q2 2026 | $7.0m | $440.1k | 0.06 |
Biggest buyers
| First Light Asset Management, LLC | Added | +153.0k |
| MILLENNIUM MANAGEMENT LLC | Added | +107.2k |
| Vestal Point Capital, LP | Added | +97.0k |
| CITADEL ADVISORS LLC | New | +90.4k |
| D. E. Shaw & Co., Inc. | Added | +70.4k |
| JANE STREET GROUP, LLC | New | +65.8k |
| SECTORAL ASSET MANAGEMENT INC | Added | +52.0k |
| Ikarian Capital, LLC | Added | +48.3k |
| HRT FINANCIAL LP | New | +44.5k |
| Trexquant Investment LP | New | +37.0k |
Biggest sellers
| BRAIDWELL LP | Reduced | -250.3k |
| Opaleye Management Inc. | Sold out | -123.0k |
| PRICE T ROWE ASSOCIATES INC /MD/ | Reduced | -116.1k |
| Point72 Asset Management, L.P. | Sold out | -68.6k |
| MARSHALL WACE, LLP | Reduced | -57.5k |
| ExodusPoint Capital Management, LP | Reduced | -48.4k |
| Prosight Management, LP | Reduced | -40.1k |
| TD Asset Management Inc | Sold out | -20.4k |
| Soleus Capital Management, L.P. | Reduced | -20.0k |
| SEI INVESTMENTS CO | Reduced | -19.8k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $6.1m176.1k shares |
| CITADEL ADVISORS LLC | Reduced | $584.4k17.0k shares |
| GROUP ONE TRADING LLC | Reduced | $343.8k10.0k shares |
| SIMPLEX TRADING, LLC | Reduced | $3.4k100 shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $398.8k11.6k shares |
| SIMPLEX TRADING, LLC | Reduced | $41.2k1.2k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
SPRINGER TIMOTHY A
13D · may seek influence
+2.3 pts · filed 2025-04-07
Stated purposeN/A Full filing |
31.5% |
| FMR LLC 13G · institution +4.7 pts · filed 2025-05-12 | 15.0% |
| MCGUIRE TERRANCE 13D · may seek influence no change · filed 2025-04-07 | 6.3% |
| TCG Crossover GP II, LLC 13G · passive investor new · filed 2026-02-27 | 6.2% |
| Aberdeen Group plc 13G · institution new · filed 2026-01-29 | 6.1% |
Fell to 5% or below in the last year: EcoR1 Capital, LLC (0.0%, 2025-11-14), Deep Track Capital, LP (0.0%, 2025-11-14)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 1 | $10.1m | 0 | — | — |
| Q1 2025 | 2 | $40.2m | 0 | — | — |
| Q2 2025 | 1 | $10.8m | 1 | $8.6m | — |
| Q3 2025 | 0 | — | 0 | — | — |
| Q4 2025 | 0 | — | 0 | — | — |
| Q1 2026 | 2 | $182.4k | 2 | $566.6k | $566.6k |
| Q2 2026 | 0 | — | 2 | $69.0k | $69.0k |
| Q3 2026 | 0 | — | 1 | $3.1k | $3.1k |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-08-25 | McNamara Peter Chief Scientific Officer | Sold plan | $1.6k43 shares |
| 2026-08-12 | McNamara Peter Chief Scientific Officer | Sold plan | $1.5k43 shares |
| 2026-06-30 | McNamara Peter Chief Scientific Officer | Sold plan | $6.0k172 shares |
| 2026-05-04 | Ruddy Marcella K. Chief Medical Officer | Sold plan | $31.9k1.1k shares |
| 2026-04-01 | Ruddy Marcella K. Chief Medical Officer | Sold plan | $31.1k1.0k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| FMR LLC 0.00% of their portfolio | 2.8m $97.3m | Added +13.9k |
| TCG Crossover Management, LLC 1.00% of their portfolio | 1.2m $41.4m | Unchanged |
| Aberdeen Group plc 0.06% of their portfolio | 1.1m $39.3m | Unchanged |
| BlackRock, Inc. 0.00% of their portfolio | 862.6k $29.7m | Added +2.2k |
| First Light Asset Management, LLC 1.67% of their portfolio | 800.7k $27.5m | Added +153.0k |
| BAKER BROS. ADVISORS LP 0.10% of their portfolio | 607.8k $20.9m | Unchanged |
| 5AM Venture Management, LLC 7.24% of their portfolio | 606.7k $20.9m | Unchanged |
| BRAIDWELL LP 0.76% of their portfolio | 596.9k $20.5m | Reduced -250.3k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 488.8k $16.8m | Added +15.3k |
| Vestal Point Capital, LP 0.34% of their portfolio | 425.0k $14.6m | Added +97.0k |
| Bollard Group LLC 0.32% of their portfolio | 303.0k $10.4m | Unchanged |
| KENNEDY CAPITAL MANAGEMENT LLC 0.17% of their portfolio | 282.2k $9.7m | Reduced -4.5k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 270.5k $9.3m | Added +2.2k |
| ORBIMED ADVISORS LLC 0.15% of their portfolio | 226.6k $7.8m | Unchanged |
| STATE STREET CORP 0.00% of their portfolio | 219.9k $7.6m | Added +6.4k |
| Ikarian Capital, LLC 1.16% of their portfolio | 205.8k $7.1m | Added +48.3k |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 186.6k $6.4m | Added +70.4k |
| MARSHALL WACE, LLP 0.00% of their portfolio | 172.1k $5.9m | Reduced -57.5k |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 165.5k $5.7m | Added +107.2k |
| Squarepoint Ops LLC 0.01% of their portfolio | 145.0k $5.0m | Reduced -19.4k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 142.4k $4.9m | Reduced -984 |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 117.4k $4.0m | Added +4.8k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 113.9k $3.9m | Added +35.6k |
| Soleus Capital Management, L.P. 0.12% of their portfolio | 101.7k $3.5m | Reduced -20.0k |
| Woodline Partners LP 0.01% of their portfolio | 100.0k $3.4m | Unchanged |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 94.4k $3.2m | Added +30.8k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 90.4k $3.1m | New |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 73.9k $2.5m | Added +11.5k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 72.7k $2.5m | Added +8.5k |
| SECTORAL ASSET MANAGEMENT INC 1.70% of their portfolio | 71.0k $2.4m | Added +52.0k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 68.4k $2.4m | Added +499 |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 65.8k $2.3m | New |
| MORGAN STANLEY 0.00% of their portfolio | 65.4k $2.2m | Added +525 |
| Connor, Clark & Lunn Investment Management Ltd. 0.00% of their portfolio | 64.9k $2.2m | Reduced -2.1k |
| BOOTHBAY FUND MANAGEMENT, LLC 0.04% of their portfolio | 60.8k $2.1m | Added +14.6k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 55.4k $1.8m | Reduced -3.5k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 48.0k $1.7m | Reduced -116.1k |
| Tetragon Partners GP Ltd 0.26% of their portfolio | 46.5k $1.6m | Added +8.9k |
| PFM Health Sciences, LP 0.14% of their portfolio | 45.6k $1.6m | Reduced -498 |
| HRT FINANCIAL LP 0.00% of their portfolio | 44.5k $1.5m | New |
| Jump Financial, LLC 0.01% of their portfolio | 43.4k $1.5m | Added +302 |
| Prosight Management, LP 0.24% of their portfolio | 39.7k $1.4m | Reduced -40.1k |
| Trexquant Investment LP 0.01% of their portfolio | 37.0k $1.3m | New |
| Aldebaran Capital, LLC 0.95% of their portfolio | 36.8k $1.3m | Reduced -387 |
| ExodusPoint Capital Management, LP 0.01% of their portfolio | 35.2k $1.2m | Reduced -48.4k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 31.4k $1.1m | Added +2.2k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 30.4k $1.0m | Added +1.3k |
| MONIMUS CAPITAL MANAGEMENT, LP 0.25% of their portfolio | 28.1k $967.4k | Added +1.4k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 25.2k $867.9k | Added +487 |
| ALPS ADVISORS INC 0.00% of their portfolio | 19.1k $658.2k | Added +3.9k |
| Fisher Asset Management, LLC 0.00% of their portfolio | 19.1k $657.3k | New |
| AMERICAN CENTURY COMPANIES INC 0.00% of their portfolio | 19.0k $653.2k | Added +6.5k |
| Quadrature Capital Ltd 0.01% of their portfolio | 18.1k $621.1k | New |
| SEI INVESTMENTS CO 0.00% of their portfolio | 17.0k $585.4k | Reduced -19.8k |
| Clearstead Advisors, LLC 0.01% of their portfolio | 16.6k $571.7k | Reduced -10.1k |
| UBS Group AG 0.00% of their portfolio | 15.1k $517.5k | Reduced -14.9k |
| ADAR1 Capital Management, LLC 0.02% of their portfolio | 14.5k $498.5k | Added +1.5k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 13.8k $473.4k | Reduced -254 |
| Nuveen, LLC 0.00% of their portfolio | 13.5k $464.5k | Added +1.5k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 11.0k $379.6k | Reduced -423 |
| Virtus Investment Advisers, LLC 0.09% of their portfolio | 10.8k $371.5k | Reduced -3.0k |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 10.4k $359.0k | Added +366 |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 10.0k $345.1k | Added +694 |
| Brevan Howard Capital Management LP 0.00% of their portfolio | 9.6k $329.1k | New |
| BARCLAYS PLC 0.00% of their portfolio | 9.1k $313.8k | Added +2.4k |
| Creative Planning 0.00% of their portfolio | 9.0k $308.0k | Reduced -3.5k |
| FOX RUN MANAGEMENT, L.L.C. 0.05% of their portfolio | 8.9k $304.7k | New |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 8.8k $301.3k | Added +4.8k |
| GSA CAPITAL PARTNERS LLP 0.02% of their portfolio | 8.3k $284.0k | Reduced -10.6k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 7.5k $230.6k | New |
| AlphaCentric Advisors LLC 0.20% of their portfolio | 6.9k $238.8k | Added +99 |
| MetLife Investment Management, LLC 0.00% of their portfolio | 6.7k $231.1k | Unchanged |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 6.6k $227.5k | Reduced -10.3k |
| Invesco Ltd. 0.00% of their portfolio | 6.4k $219.6k | Reduced -1.3k |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.00% of their portfolio | 6.1k $208.3k | New |
| Rangeley Capital, LLC 0.19% of their portfolio | 6.0k $206.2k | New |
| Velan Capital Investment Management LP 0.13% of their portfolio | 6.0k $206.2k | New |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 6.0k $206.1k | Reduced -7.9k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 5.6k $191.4k | Added +4.7k |
| CITIGROUP INC 0.00% of their portfolio | 5.5k $190.7k | Added +4.4k |
| China Universal Asset Management Co., Ltd. 0.01% of their portfolio | 5.5k $189.2k | Reduced -829 |
| NISA INVESTMENT ADVISORS, LLC 0.00% of their portfolio | 5.4k $185.6k | Added +400 |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 5.1k $176.9k | Added +2.3k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 4.7k $161.4k | Reduced -521 |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 4.6k $158.1k | Unchanged |
| Police & Firemen's Retirement System of New Jersey 0.00% of their portfolio | 2.6k $90.7k | Unchanged |
| Quantbot Technologies LP 0.00% of their portfolio | 1.8k $62.5k | New |
| Ameritas Investment Partners, Inc. 0.00% of their portfolio | 1.1k $38.6k | Unchanged |
| US BANCORP \DE\ 0.00% of their portfolio | 1.1k $37.1k | Reduced -56 |
| Legal & General Group Plc 0.00% of their portfolio | 1.0k $34.4k | Unchanged |
| Mirae Asset Global Investments Co., Ltd. 0.00% of their portfolio | 844 $29.0k | Reduced -135 |
| Chung Wu Investment Group, LLC 0.02% of their portfolio | 800 $27.5k | New |
| Arax Advisory Partners 0.00% of their portfolio | 725 $24.9k | New |
| Tower Research Capital LLC (TRC) 0.00% of their portfolio | 661 $22.7k | Reduced -253 |
| State of Wyoming 0.00% of their portfolio | 601 $20.7k | New |
| HighMark Wealth Management LLC 0.01% of their portfolio | 587 $20.2k | Unchanged |
| SIMPLEX TRADING, LLC 0.00% of their portfolio | 439 $15.1k | Reduced -912 |
| GF FUND MANAGEMENT CO. LTD. 0.00% of their portfolio | 400 $13.8k | Reduced -15 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 382 $13.1k | Unchanged |
| Rockefeller Capital Management L.P. 0.00% of their portfolio | 370 $12.7k | Unchanged |