Metsera, Inc.
Metsera, Inc. (MTSR) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · MTSR · as of Sep 30, 2025
Ownership Breakdown
167
Institutional Holders
▲ 55 vs Q2
$3.39B
Total Inst. Value
▲ $1.65B vs Q2
105.38M
Shares Outstanding
freeFloat 45.69%
64.76M
13F Shares Held
▲ 3.65M 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
MTSR largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
FMR LLC pharmaceutical preparations | 13.89M | 13.25% | 13.25% | $726.97B | Nov 13, 2025 | ▼ 1.87M |
VANGUARD GROUP INC pharmaceutical preparations | 5.82M | 5.55% | 5.55% | $304.82B | Nov 7, 2025 | ▲ 4.33M |
JANUS HENDERSON GROUP PLC pharmaceutical preparations | 5.35M | 5.10% | 5.10% | $280.08B | Nov 14, 2025 | ▲ 1.96M |
BLACKROCK, INC. pharmaceutical preparations | 3.84M | 3.66% | 3.66% | $200.70B | Nov 12, 2025 | ▲ 2.60M |
ALPHABET INC. pharmaceutical preparations | 3.78M | 3.61% | 3.61% | $197.99B | Nov 7, 2025 | ▼ 1.18M |
VR ADVISER, LLC pharmaceutical preparations | 3.75M | 3.58% | 3.58% | $196.27B | Nov 14, 2025 | — held |
WELLINGTON MANAGEMENT GROUP LLP pharmaceutical preparations | 3.66M | 3.49% | 3.49% | $191.50B | Nov 14, 2025 | ▲ 232.0K |
SOFTBANK GROUP CORP. pharmaceutical preparations | 3.65M | 3.48% | 3.48% | $191.25B | Nov 14, 2025 | ▼ 1.17M |
HBK INVESTMENTS L P pharmaceutical preparations | 3.20M | 3.05% | 3.05% | $167.46B | Nov 14, 2025 | NEW |
STATE STREET CORP pharmaceutical preparations | 2.51M | 2.39% | 2.39% | $131.40B | Nov 14, 2025 | ▲ 1.91M |
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
23
Increased
+14.88M shares13
New Positions
first time holders6
Decreased
−5.12M shares0
Sold Out
fully exitedNet shares change (top 50)
+9.76M
+14.88M / −5.12M
Net new holders
+30
13 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
MTSR insider trading · insider activity
Source: SEC Form 4
14
Buy transactions
38
Sell transactions
0.37
Buy/Sell ratio
$77M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
FMR LLC See Remark 1 | Nov 13, 2025 | J-Other | 2,230,450 | $0.00 | $22.305 | 0 | Form 4 ↗ |
ARCH Venture Partners XII, LLC
| Nov 13, 2025 | D-Return | 8,313,680 | $0.00 | $83.137 | 0 | Form 4 ↗ |
Marso Steven CHIEF MEDICAL OFFICER | Nov 13, 2025 | D-Return | 17,000 | $0.00 | $0.17 | 0 | Form 4 ↗ |
Marso Steven CHIEF MEDICAL OFFICER | Nov 13, 2025 | D-Return | 21,279 | $0.26 | $5.5K | 0 | Form 4 ↗ |
Marso Steven CHIEF MEDICAL OFFICER | Nov 13, 2025 | D-Return | 120,000 | $29.25 | $3.51M | 0 | Form 4 ↗ |
BERNS PAUL L director | Nov 13, 2025 | D-Return | 24,188 | $29.25 | $707.5K | 0 | Form 4 ↗ |
BERNS PAUL L director | Nov 13, 2025 | D-Return | 223,430 | $8.18 | $1.83M | 0 | Form 4 ↗ |
BERNS PAUL L director | Nov 13, 2025 | D-Return | 957,559 | $0.00 | $9.576 | 0 | Form 4 ↗ |
Lang Matthew CHIEF LEGAL OFFICER | Nov 13, 2025 | D-Return | 12,500 | $0.00 | $0.125 | 0 | Form 4 ↗ |
Lang Matthew CHIEF LEGAL OFFICER | Nov 13, 2025 | D-Return | 46,875 | $29.25 | $1.37M | 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
Metsera, Inc. (MTSR) is primarily owned by institutional investors, who hold approximately 61.5% of total shares outstanding. Company insiders own approximately 54.31%, while retail and public investors account for the remaining 0.00%.
The largest institutional shareholder of Metsera, Inc. is FMR LLC, holding approximately 13.89 million shares — equal to 13.25% of outstanding shares — as of September 30, 2025.
A total of 167 institutional investors currently hold MTSR stock, with a combined institutional value of approximately $3.39 billion as of the most recent 13F filing period.
Frequently asked questions
MTSR ownershipMetsera, Inc. (MTSR) is primarily owned by institutional investors, who hold approximately 61.5% of shares. The largest shareholder is FMR LLC with a 13.25% stake. Company insiders hold 54.31%. Data sourced from SEC Form 13F as of September 30, 2025.