Larimar Therapeutics, Inc. (LRMR) Ownership
LRMR ownership summary
as of October 18, 2026- Institutions
- 93.7% of shares outstanding
- Insiders
- 1.19% of shares outstanding
- Shares outstanding
- 103.9M
- Float
- 57.9M shares available to trade
- Short interest
- 22.85% 15.4M shares short
- Days to cover
- 11.22 short interest up 10.6% vs prior month
- Institutions 93.65%
- Insiders 1.19%
- Other investors 5.16%
LRMR top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Deerfield Management Co | 34.28% | 35.6M | $70.7M | — | June 30, 2026 |
| 2 | Blue Owl Capital Holdings LP | 8.82% | 9.2M | $18.2M | +2.0M (+28.7%) | June 30, 2026 |
| 3 | BlackRock Inc | 5.47% | 5.7M | $11.3M | +1.9M (+51.3%) | June 30, 2026 |
| 4 | Defilade Capital Management, L.P. | 3.53% | 3.7M | $7.3M | +3.7M (0.0%) | June 30, 2026 |
| 5 | Driehaus Capital Management LLC | 3.05% | 3.2M | $6.3M | +229,024 (+7.8%) | June 30, 2026 |
| 6 | Vanguard Capital Management, LLC | 2.86% | 3.0M | $5.9M | +108,552 (+3.8%) | June 30, 2026 |
| 7 | RTW INVESTMENTS, LLC | 2.47% | 2.6M | $5.1M | +1.1M (+71.1%) | June 30, 2026 |
| 8 | AQR Capital Management LLC | 2.28% | 2.4M | $4.7M | +1.6M (+190.1%) | June 30, 2026 |
| 9 | Marshall Wace Asset Management Ltd | 1.94% | 2.0M | $4.0M | +1.1M (+115.6%) | June 30, 2026 |
| 10 | Dafna Capital Management LLC | 1.93% | 2.0M | $4.0M | −21,000 (−1.0%) | June 30, 2026 |
| 11 | The Goldman Sachs Group Inc | 1.69% | 1.8M | $3.5M | +191,325 (+12.3%) | June 30, 2026 |
| 12 | Geode Capital Management, LLC | 1.62% | 1.7M | $3.3M | +570,242 (+51.4%) | June 30, 2026 |
| 13 | Qube Research & Technologies | 1.58% | 1.6M | $3.3M | +793,398 (+93.6%) | June 30, 2026 |
| 14 | Citadel Advisors Llc | 1.40% | 1.5M | $2.9M | +937,693 (+180.6%) | June 30, 2026 |
| 15 | State Street Corp | 1.36% | 1.4M | $2.8M | +500,478 (+54.9%) | June 30, 2026 |
| 16 | Vanguard Portfolio Management, LLC | 1.35% | 1.4M | $2.8M | +996,614 (+245.1%) | June 30, 2026 |
| 17 | Woodline Partners LP | 1.35% | 1.4M | $2.8M | — | June 30, 2026 |
| 18 | Millennium Management LLC | 1.28% | 1.3M | $2.6M | −2.3M (−63.2%) | June 30, 2026 |
| 19 | Dimensional Fund Advisors, Inc. | 0.93% | 961K | $1.9M | +162,621 (+20.4%) | June 30, 2026 |
| 20 | FMR Inc | 0.90% | 937K | $1.9M | +873,798 (+1,374.5%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 16 holders added 16.7M shares and 2 cut 2.3M.
LRMR top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 2.12% | 2.2M | $4.4M | — | August 31, 2026 |
| 2 | iShares Russell 2000 ETF | 1.67% | 1.7M | $3.4M | −19,968 (−1.1%) | September 30, 2026 |
| 3 | Fidelity Enhanced Small Cap Core ETF | 0.93% | 971K | $1.9M | +2,034 (+0.2%) | September 30, 2026 |
| 4 | Heptagon Driehaus US Micro Cap Eq C$ Acc | 0.82% | 849K | $1.7M | — | August 31, 2026 |
| 5 | Fidelity Small Cap Index | 0.70% | 727K | $1.4M | +2,751 (+0.4%) | July 31, 2026 |
| 6 | Vanguard Explorer Inv | 0.63% | 659K | $1.3M | +659,133 (0.0%) | June 30, 2026 |
| 7 | iShares Russell 2000 Growth ETF | 0.61% | 631K | $1.3M | −798 (−0.1%) | September 30, 2026 |
| 8 | MEDICAL BioHealth EUR Acc | 0.50% | 522K | $1.0M | +110 (+0.0%) | August 31, 2026 |
| 9 | Vanguard Russell 2000 ETF | 0.37% | 388K | $771,004 | +4,984 (+1.3%) | September 30, 2026 |
| 10 | iShares Biotechnology ETF | 0.36% | 375K | $744,173 | −2,840 (−0.8%) | September 30, 2026 |
| 11 | Dimensional US Small Cap ETF | 0.33% | 341K | $676,466 | — | September 30, 2026 |
| 12 | Driehaus Micro Cap Growth USD | 0.33% | 339K | $672,887 | — | August 31, 2026 |
| 13 | Fidelity Extended Market Index | 0.30% | 307K | $609,093 | +12,429 (+4.2%) | August 31, 2026 |
| 14 | iShares Micro-Cap ETF | 0.20% | 210K | $416,667 | −1,448 (−0.7%) | September 30, 2026 |
| 15 | JPMorgan Small Cap Value I | 0.17% | 179K | $354,831 | — | August 31, 2026 |
| 16 | Vanguard Health Care ETF | 0.17% | 174K | $346,170 | +189 (+0.1%) | September 30, 2026 |
| 17 | Fidelity Nasdaq Composite Index | 0.16% | 165K | $327,394 | +102,866 (+165.7%) | August 31, 2026 |
| 18 | Adara Smaller Companies | 0.16% | 165K | $327,092 | — | August 31, 2026 |
| 19 | DFA US Micro Cap I | 0.16% | 163K | $323,894 | +28,898 (+21.5%) | August 31, 2026 |
| 20 | Schwab Small Cap Index | 0.16% | 162K | $321,828 | — | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
LRMR insider transactions
latest 2| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-02-27 | James E Flynn | Buy | $5.00 | 5,000,000 | $25.0M |
| 2025-07-31 | James E Flynn | Buy | $3.20 | 9,375,000 | $30.0M |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
LRMR shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns LRMR
Institutional investors own 93.7% of Larimar Therapeutics's shares and insiders 1.19%. The largest holder is Deerfield Management Co with 34.28% of the shares (35.6M), as of June 30, 2026. Among the top 20 institutions, 16 added shares and 2 reduced their stake in the latest filings. Short interest is 22.85% of the float, or 11.22 days of average trading volume. The share count rose 8,418.3% since 2014.
Related: LRMR analyst forecast, LRMR key metrics. See the LRMR stock overview for the latest quote and news.
LRMR ownership FAQ
Who owns the most Larimar Therapeutics stock?
The largest shareholders of Larimar Therapeutics are Deerfield Management Co (34.28%), Blue Owl Capital Holdings LP (8.82%), BlackRock Inc (5.47%), Defilade Capital Management, L.P. (3.53%), Driehaus Capital Management LLC (3.05%).
What percentage of Larimar Therapeutics is owned by institutions?
Institutions hold 93.7% of Larimar Therapeutics's shares outstanding; insiders hold 1.19%.
Which funds own Larimar Therapeutics?
The largest fund holders of Larimar Therapeutics are Vanguard MStar Total Stk Mkt Idx Invest (2.12%), iShares Russell 2000 ETF (1.67%), Fidelity Enhanced Small Cap Core ETF (0.93%), Heptagon Driehaus US Micro Cap Eq C$ Acc (0.82%), Fidelity Small Cap Index (0.70%).
What is Larimar Therapeutics's short interest?
15.4M shares of Larimar Therapeutics were sold short, 22.85% of the float; at the average daily volume it would take 11.22 days to cover.
Are insiders buying or selling Larimar Therapeutics?
Of the latest 2 reported insider transactions in Larimar Therapeutics (since July 31, 2025), 2 were purchases and 0 were sales.
How many shares of Larimar Therapeutics are outstanding?
Larimar Therapeutics has 103.9M shares outstanding, of which 57.9M are in the public float.