Larimar Therapeutics, Inc.
Larimar Therapeutics, Inc. (LRMR) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · LRMR · as of Mar 31, 2025
Ownership Breakdown
105
Institutional Holders
▼ 18 vs Q4
$131.86M
Total Inst. Value
▼ $113.63M vs Q4
85.58M
Shares Outstanding
freeFloat 59.78%
60.83M
13F Shares Held
▼ 2.61M vs Q4
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
LRMR largest shareholders · institutional ownership
Q1 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) pharmaceutical preparations | 21.23M | 33.19% | 33.19% | $45.65B | May 15, 2025 | — held |
RA CAPITAL MANAGEMENT, L.P. pharmaceutical preparations | 6.05M | 9.45% | 9.45% | $13.00B | May 15, 2025 | — held |
JANUS HENDERSON GROUP PLC pharmaceutical preparations | 5.57M | 8.71% | 8.71% | $13.07B | May 15, 2025 | ▼ 871.3K |
BLUE OWL CAPITAL HOLDINGS LP pharmaceutical preparations | 4.78M | 7.47% | 7.47% | $10.27B | May 15, 2025 | ▲ 125.0K |
BLACKROCK, INC. pharmaceutical preparations | 3.12M | 4.88% | 4.88% | $6.72B | May 2, 2025 | ▼ 141.9K |
GOLDMAN SACHS GROUP INC pharmaceutical preparations | 2.67M | 4.18% | 4.18% | $5.74B | Jun 27, 2025 | ▼ 1.48M |
VANGUARD GROUP INC pharmaceutical preparations | 2.22M | 3.47% | 3.47% | $4.77B | May 9, 2025 | ▲ 24.9K |
OPALEYE MANAGEMENT INC. pharmaceutical preparations | 1.91M | 2.99% | 2.99% | $4.12B | May 15, 2025 | NEW |
ALYESKA INVESTMENT GROUP, L.P. pharmaceutical preparations | 1.44M | 2.26% | 2.26% | $3.10B | May 15, 2025 | ▲ 458.4K |
RENAISSANCE TECHNOLOGIES LLC pharmaceutical preparations | 975.0K | 1.52% | 1.52% | $2.10B | May 14, 2025 | ▲ 461.4K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q1 2025 vs prior quarter
Q1 2025
21
Increased
+3.41M shares4
New Positions
first time holders18
Decreased
−4.32M shares0
Sold Out
fully exitedNet shares change (top 50)
903.8K
+3.41M / −4.32M
Net new holders
+7
4 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
LRMR insider trading · insider activity
Source: SEC Form 4
Insiders have been net buyers of shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
6
Buy transactions
0
Sell transactions
0.00
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Flynn James E * Director by Deputization | May 19, 2026 | Award | 55,150 | $3.33 | $183.6K | 55.1K | Form 4 ↗ |
LEFF JONATHAN S director | May 19, 2026 | Award | 55,150 | $3.33 | $183.6K | 55.1K | Form 4 ↗ |
SHERMAN JEFFREY W director | May 19, 2026 | Award | 55,150 | $3.33 | $183.6K | 55.1K | Form 4 ↗ |
Truitt Joseph director | May 19, 2026 | Award | 55,150 | $3.33 | $183.6K | 55.1K | Form 4 ↗ |
THOMAS FRANK E director | May 19, 2026 | Award | 55,150 | $3.33 | $183.6K | 55.1K | Form 4 ↗ |
Hamilton Thomas Edward director | May 19, 2026 | Award | 55,150 | $3.33 | $183.6K | 55.1K | Form 4 ↗ |
Flynn James E * Director by Deputization | Feb 27, 2026 | Purchase | 1,084,012 | $5.00 | $5.42M | 10.62M | Form 4 ↗ |
Flynn James E * Director by Deputization | Feb 27, 2026 | Purchase | 1,084,010 | $5.00 | $5.42M | 10.62M | Form 4 ↗ |
Flynn James E * Director by Deputization | Feb 27, 2026 | Purchase | 831,978 | $5.00 | $4.16M | 8.15M | Form 4 ↗ |
Flynn James E * Director by Deputization | Feb 27, 2026 | Purchase | 2,000,000 | $5.00 | $10.00M | 6.21M | 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
Larimar Therapeutics, Inc. (LRMR) is primarily owned by institutional investors, who hold approximately 71.1% of total shares outstanding. Company insiders own approximately 40.22%, while retail and public investors account for the remaining 0.00%.
The largest institutional shareholder of Larimar Therapeutics, Inc. is DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C), holding approximately 21.23 million shares — equal to 33.19% of outstanding shares — as of March 31, 2025.
A total of 105 institutional investors currently hold LRMR stock, with a combined institutional value of approximately $131,864,707 as of the most recent 13F filing period.
Frequently asked questions
LRMR ownershipLarimar Therapeutics, Inc. (LRMR) is primarily owned by institutional investors, who hold approximately 71.1% of shares. The largest shareholder is DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) with a 33.19% stake. Company insiders hold 40.22%. Data sourced from SEC Form 13F as of March 31, 2025.