Tourmaline Bio, Inc.
Tourmaline Bio, Inc. (TRML) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · TRML · as of Sep 30, 2025
Ownership Breakdown
141
Institutional Holders
▲ 34 vs Q2
$1.04B
Total Inst. Value
▲ $650.37M vs Q2
25.69M
Shares Outstanding
freeFloat 65.41%
21.64M
13F Shares Held
▼ 2.42M vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
TRML largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
AVORO CAPITAL ADVISORS LLC biological products, (no diagnostic substances) | 2.56M | 9.92% | 9.92% | $122.23B | Nov 14, 2025 | — held |
QVT FINANCIAL LP biological products, (no diagnostic substances) | 2.15M | 8.37% | 8.37% | $103.06B | Nov 14, 2025 | — held |
BLACKROCK, INC. biological products, (no diagnostic substances) | 1.52M | 5.89% | 5.89% | $72.60B | Nov 12, 2025 | ▼ 116.2K |
TCG CROSSOVER MANAGEMENT, LLC biological products, (no diagnostic substances) | 1.31M | 5.09% | 5.09% | $62.74B | Nov 17, 2025 | ▼ 165.8K |
PFIZER INC biological products, (no diagnostic substances) | 1.27M | 4.94% | 4.94% | $60.85B | Nov 13, 2025 | — held |
VANGUARD GROUP INC biological products, (no diagnostic substances) | 1.17M | 4.53% | 4.53% | $55.75B | Nov 7, 2025 | ▼ 41.4K |
FIL LTD biological products, (no diagnostic substances) | 1.03M | 3.99% | 3.99% | $49.15B | Nov 13, 2025 | NEW |
MAGNETAR FINANCIAL LLC biological products, (no diagnostic substances) | 966.1K | 3.75% | 3.75% | $46.21B | Nov 13, 2025 | NEW |
QIMING U.S. VENTURES MANAGEMENT, LLC biological products, (no diagnostic substances) | 741.7K | 2.88% | 2.88% | $35.48B | Nov 10, 2025 | — held |
FIRST TRUST CAPITAL MANAGEMENT L.P. biological products, (no diagnostic substances) | 695.8K | 2.70% | 2.70% | $33.28B | Nov 17, 2025 | NEW |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
8
Increased
+1.09M shares19
New Positions
first time holders17
Decreased
−1.34M shares0
Sold Out
fully exitedNet shares change (top 50)
248.0K
+1.09M / −1.34M
Net new holders
+10
19 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
TRML insider trading · insider activity
Source: SEC Form 4
2
Buy transactions
53
Sell transactions
0.04
Buy/Sell ratio
$4M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
SIEGALL CLAY B director | Oct 28, 2025 | D-Return | 16,800 | $18.73 | $314.7K | 0 | Form 4 ↗ |
SIEGALL CLAY B director | Oct 28, 2025 | D-Return | 15,000 | $13.91 | $208.7K | 0 | Form 4 ↗ |
SIEGALL CLAY B director | Oct 28, 2025 | D-Return | 20,000 | $18.55 | $371.0K | 0 | Form 4 ↗ |
Thiara Parvinder director | Oct 28, 2025 | D-Return | 16,800 | $18.73 | $314.7K | 0 | Form 4 ↗ |
Thiara Parvinder director | Oct 28, 2025 | U-Tender | 83,782 | $48.00 | $4.02M | 0 | Form 4 ↗ |
Thiara Parvinder director | Oct 28, 2025 | D-Return | 10,000 | $9.46 | $94.6K | 0 | Form 4 ↗ |
Thiara Parvinder director | Oct 28, 2025 | D-Return | 10,000 | $13.91 | $139.1K | 0 | Form 4 ↗ |
Srivastava Sapna director | Oct 28, 2025 | D-Return | 20,000 | $9.46 | $189.2K | 0 | Form 4 ↗ |
Srivastava Sapna director | Oct 28, 2025 | D-Return | 16,800 | $18.73 | $314.7K | 0 | Form 4 ↗ |
Srivastava Sapna director | Oct 28, 2025 | D-Return | 10,000 | $13.91 | $139.1K | 0 | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Tourmaline Bio, Inc. (TRML) is primarily owned by institutional investors, who hold approximately 84.2% of total shares outstanding. Company insiders own approximately 34.59%, while retail and public investors account for the remaining 0.00%.
The largest institutional shareholder of Tourmaline Bio, Inc. is AVORO CAPITAL ADVISORS LLC, holding approximately 2.56 million shares — equal to 9.92% of outstanding shares — as of September 30, 2025.
A total of 141 institutional investors currently hold TRML stock, with a combined institutional value of approximately $1.04 billion as of the most recent 13F filing period.
Frequently asked questions
TRML ownershipTourmaline Bio, Inc. (TRML) is primarily owned by institutional investors, who hold approximately 84.2% of shares. The largest shareholder is AVORO CAPITAL ADVISORS LLC with a 9.92% stake. Company insiders hold 34.59%. Data sourced from SEC Form 13F as of September 30, 2025.