Comparable stake leader
Timothy A. Springer
SEC ownership of Tectonic Therapeutic, Inc.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001681087.
Disclosed value leader
Timothy A. Springer
Comparable rows
50/50
Latest evidence
30 Jun 2026
- Public ticker
- TECX on Nasdaq
- Parsed ownership sources
-
3/4/5, 13D/G, and 13F
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
Timothy A. Springer
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
Timothy A. Springer
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
30 Jun 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001681087
- Issuer location
- Watertown, MA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of Tectonic Therapeutic, Inc. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
Timothy A. Springer
Disclosed value leader
Timothy A. Springer
Comparable rows
50/50
Latest evidence
30 Jun 2026
3/4/5
13D/G
13F
Lead comparable stake: 32%
13D/G row: Timothy A. Springer
Showing 1-8 of 50 holder rows.
Quick read
Timothy A. Springer leads the comparable SEC ownership view at 32%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens Timothy A. Springer's linked filing trail.
Comparable ownership
Top 5
Timothy A. Springer
32%
FMR LLC
15%
Terrance McGuire
6.3%
TCG Crossover GP II, LLC
6.2%
Aberdeen Group plc
6.1%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| Timothy A. Springer |
3/4/5
13D/G
Director, 10%+ Owner
|
32%
from 13D/G
|
$98,256,953
6,034,538 shares
mixed-class rows
|
— | 09 Jun 2026 |
| FMR LLC |
13F
13D/G
Company
|
15%
from 13D/G
|
$97,294,233
2,830,378 shares
|
— | 30 Jun 2026 |
| Terrance McGuire |
13D/G
3/4/5
Director
|
6.3%
|
$14,725,503
657,976 shares
|
-$11,190,022 | 03 Apr 2025 |
| TCG Crossover GP II, LLC |
13D/G
Chen Yu
|
6.2%
|
$24,202,334
1,169,760 shares
|
$0 | 12 Feb 2026 |
| Aberdeen Group plc |
13F
13D/G
Company
|
6.1%
from 13D/G
|
$39,250,200
1,141,824 shares
|
— | 30 Jun 2026 |
| TCG Crossover Management, LLC |
13F
Company
|
6.4%
|
$41,418,128
1,204,891 shares
|
— | 30 Jun 2026 |
| BlackRock, Inc. |
13F
Company
|
4.6%
|
$29,651,600
862,592 shares
|
— | 30 Jun 2026 |
| First Light Asset Management, LLC |
13F
Company
|
4.2%
|
$27,524,958
800,726 shares
|
— | 30 Jun 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$454,677.
Buys
$182,410
Insiders: 2
Sells
$637,087
Insiders: 2
Net
-$454,677
Shares: -13,341
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 8,500
Shares: 21,841
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 215 | $0 | $7,525 | -$7,525 |
| 3-6 | 0 | 21,626 | $0 | $629,562 | -$629,562 |
| 6-9 | 8,500 | 0 | $182,410 | $0 | +$182,410 |
| 9-12 | 0 | 0 | $0 | $0 | $0 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 28 reporting-owner rows connected to Tectonic Therapeutic, Inc.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
28
Largest Forms 3/4/5 holder
Timothy A. Springer
Net 12M change
-$454,677
Latest report
12 Aug 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Timothy A. Springer | Director, 10%+ Owner | $98,256,953 | Mixed | 09 Jun 2026 | ||
| Alise Reicin | Chief Executive Officer, Director | $13,527,853 | +$52,750 | +0.39% | Mixed | 20 Jun 2026 |
| Terrance McGuire | Director | $9,799,360 | Filing P/S | 09 Jun 2025 | ||
| Marcella K. Ruddy | Chief Medical Officer | $2,030,460 | -$363,000 | -15% | Filing P/S | 04 May 2026 |
| Peter McNamara | Chief Scientific Officer | $1,934,975 | -$274,087 | -12% | Filing P/S | 12 Aug 2026 |
| Daniel Lochner | Chief Financial Officer | $1,329,534 | +$129,660 | +11% | Mixed | 11 Jun 2026 |
| Marc Schwabish | Chief Business Officer | $1,029,080 | Mixed | 04 Mar 2026 | ||
| Braden M. Leonard | Former 10% owner of AVROBIO | $563,795 | Mixed | 20 Jun 2024 | ||
| Geoffrey Mackay | President & CEO, Director | $360,981 | Mixed | 08 Feb 2023 | ||
| Azadeh Golipour | Chief Technology Officer | $201,602 | Mixed | 01 Feb 2024 | ||
| Erik Ostrowski | Interim CEO, President and CFO | $179,740 | Mixed | 01 Feb 2024 | ||
| Christian Cortis | Chief Operating Officer | $164,278 | Mixed | 20 Jun 2024 | ||
| Steven N. Avruch | Chief Legal Officer | $145,161 | Mixed | 01 Feb 2024 | ||
| Essra Ridha | Chief Medical Officer | $137,463 | Mixed | 01 Feb 2024 | ||
| Deanna M. Petersen | Chief Business Officer | $104,052 | Mixed | 08 Feb 2023 | ||
| Stefan Vitorovic | Director | $36,106 | Mixed | 09 Jun 2026 | ||
| Praveen P. Tipirneni | Director | $3,948 | Mixed | 09 Jun 2026 | ||
| Annalisa Jenkins | Director | Mixed | 06 Jun 2023 | |||
| Philip J. Vickers | Director | Mixed | 06 Jun 2023 | |||
| Bruce Booth | Director | Mixed | 06 Jun 2023 |
Recent insider transactions for Tectonic Therapeutic, Inc.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Peter McNamara | TECX | Common Stock | Sale | -0.08% | $1,505 | $35.00 | -43 | 55,285 | 12 Aug 2026 | Direct |
| Peter McNamara | TECX | Common Stock | Options Exercise | 0.08% | 43 | 55,328 | 12 Aug 2026 | Direct | ||
| Peter McNamara | TECX | Employee Stock Option (Right to Buy) | Options Exercise | -0.55% | -43 | 7,830 | 12 Aug 2026 | Direct | ||
| Peter McNamara | TECX | Common Stock | Sale | -0.31% | $6,020 | $35.00 | -172 | 55,285 | 30 Jun 2026 | Direct |
| Peter McNamara | TECX | Common Stock | Options Exercise | 0.31% | 172 | 55,457 | 30 Jun 2026 | Direct | ||
| Peter McNamara | TECX | Employee Stock Option (Right to Buy) | Options Exercise | -2.14% | -172 | 7,873 | 30 Jun 2026 | Direct | ||
| Alise Reicin | TECX | Common Stock | Tax liability | -0.3% | -924 | 310,623 | 20 Jun 2026 | Direct | ||
| Daniel Lochner | TECX | Performance Stock Option (Right to Buy) | Award | 7,500 | 7,500 | 11 Jun 2026 | Direct | |||
| Timothy A. Springer | TECX | Stock Option (Right to Buy) | Award | 10,200 | 10,200 | 09 Jun 2026 | Direct | |||
| Praveen P. Tipirneni | TECX | Stock Option (Right to Buy) | Award | 10,200 | 10,200 | 09 Jun 2026 | Direct | |||
| Phillip B. Donenberg | TECX | Stock Option (Right to Buy) | Award | 10,200 | 10,200 | 09 Jun 2026 | Direct | |||
| Stefan Vitorovic | TECX | Stock Option (Right to Buy) | Award | 10,200 | 10,200 | 09 Jun 2026 | Direct | |||
| Jessica Caroline Chutter | TECX | Stock Option (Right to Buy) | Award | 20,400 | 20,400 | 08 Jun 2026 | Direct | |||
| Marcella K. Ruddy | TECX | Common Stock | Sale | -1.55% | $31,950 | $30.00 | -1,065 | 67,682 | 04 May 2026 | Direct |
| Marcella K. Ruddy | TECX | Common Stock | Sale | -1.43% | $31,050 | $31.05 | -1,000 | 68,747 | 01 Apr 2026 | Direct |
| Francois Nader | TECX | Stock Option (Right to Buy) | Award | 20,400 | 20,400 | 01 Apr 2026 | Direct | |||
| Marcella K. Ruddy | TECX | Common Stock | Sale | -12.5% | $300,000 | $30.00 | -10,000 | 69,747 | 06 Mar 2026 | Direct |
| Peter McNamara | TECX | Common Stock | Sale | -10.2% | $188,935 | $30.17 | -6,262 | 55,285 | 06 Mar 2026 | Direct |
| Peter McNamara | TECX | Common Stock | Options Exercise | 4.61% | 2,715 | 61,547 | 06 Mar 2026 | Direct | ||
| Peter McNamara | TECX | Employee Stock Option (Right to Buy) | Options Exercise | -25.2% | -2,715 | 8,045 | 06 Mar 2026 | Direct | ||
| Alise Reicin | TECX | Common Stock | Award | 32.6% | 76,500 | 311,547 | 04 Mar 2026 | Direct | ||
| Alise Reicin | TECX | Employee Stock Option (Right to Buy) | Award | 69,250 | 69,250 | 04 Mar 2026 | Direct | |||
| Marc Schwabish | TECX | Common Stock | Award | 75.5% | 19,500 | 45,314 | 04 Mar 2026 | Direct | ||
| Marc Schwabish | TECX | Employee Stock Option (Right to Buy) | Award | 17,750 | 17,750 | 04 Mar 2026 | Direct | |||
| Peter McNamara | TECX | Common Stock | Sale | -2.73% | $41,250 | $25.00 | -1,650 | 58,832 | 04 Mar 2026 | Direct |
| Peter McNamara | TECX | Common Stock | Award | 61.4% | 23,000 | 60,482 | 04 Mar 2026 | Direct | ||
| Peter McNamara | TECX | Employee Stock Option (Right to Buy) | Award | 21,000 | 21,000 | 04 Mar 2026 | Direct | |||
| Daniel Lochner | TECX | Common Stock | Award | 82.7% | 26,500 | 58,544 | 04 Mar 2026 | Direct | ||
| Daniel Lochner | TECX | Employee Stock Option (Right to Buy) | Award | 24,250 | 24,250 | 04 Mar 2026 | Direct | |||
| Marcella K. Ruddy | TECX | Common Stock | Award | 49.8% | 26,500 | 79,747 | 04 Mar 2026 | Direct | ||
| Marcella K. Ruddy | TECX | Employee Stock Option (Right to Buy) | Award | 24,250 | 24,250 | 04 Mar 2026 | Direct | |||
| Peter McNamara | TECX | Common Stock | Sale | -4.21% | $36,377 | $22.06 | -1,649 | 37,482 | 03 Mar 2026 | Direct |
| Alise Reicin | TECX | Common Stock | Purchase | 2.01% | $52,750 | $21.10 | 2,500 | 127,030 | 11 Feb 2026 | By Trust |
| Marc Schwabish | TECX | Common Stock | Options Exercise | 21.1% | 4,500 | 25,814 | 10 Feb 2026 | Direct | ||
| Marc Schwabish | TECX | Employee Stock Option (Right to Buy) | Options Exercise | -5.2% | -4,500 | 82,014 | 10 Feb 2026 | Direct | ||
| Daniel Lochner | TECX | Common Stock | Purchase | 23% | $129,660 | $21.61 | 6,000 | 32,044 | 10 Feb 2026 | Direct |
| Marc Schwabish | TECX | Common Stock | Tax liability | -7.06% | -1,619 | 21,314 | 04 Feb 2026 | Direct | ||
| Marcella K. Ruddy | TECX | Common Stock | Tax liability | -3.73% | -2,064 | 53,247 | 04 Feb 2026 | Direct | ||
| Alise Reicin | TECX | Common Stock | Tax liability | -1.72% | -4,104 | 235,047 | 04 Feb 2026 | Direct | ||
| Peter McNamara | TECX | Common Stock | Tax liability | -4.28% | -1,748 | 39,131 | 04 Feb 2026 | Direct | ||
| Daniel Lochner | TECX | Common Stock | Tax liability | -7.39% | -2,077 | 26,044 | 04 Feb 2026 | Direct | ||
| Alise Reicin | TECX | Common Stock | Options Exercise | 4.81% | 10,966 | 239,151 | 31 Dec 2025 | Direct | ||
| Alise Reicin | TECX | Employee Stock Option (Right to Buy) | Options Exercise | -32.3% | -10,966 | 22,957 | 31 Dec 2025 | Direct | ||
| Peter McNamara | TECX | Common Stock | Options Exercise | 20.7% | 7,000 | 40,879 | 22 Dec 2025 | Direct | ||
| Peter McNamara | TECX | Employee Stock Option (Right to Buy) | Options Exercise | -21.8% | -7,000 | 25,065 | 22 Dec 2025 | Direct | ||
| Marc Schwabish | TECX | Common Stock | Award | 22.5% | 4,210 | 22,933 | 25 Sep 2025 | Direct | ||
| Marc Schwabish | TECX | Employee Stock Option (Right to Buy) | Award | 7,650 | 7,650 | 25 Sep 2025 | Direct | |||
| Peter McNamara | TECX | Common Stock | Award | 15.5% | 4,550 | 33,879 | 25 Sep 2025 | Direct | ||
| Peter McNamara | TECX | Employee Stock Option (Right to Buy) | Award | 8,260 | 8,260 | 25 Sep 2025 | Direct | |||
| Daniel Lochner | TECX | Common Stock | Award | 23.9% | 5,430 | 28,121 | 25 Sep 2025 | Direct |
* marks a reported price that did not pass the local price check.