LARIMAR THERAPEUTICS INC LRMR
COM · Common Stock · CUSIP 517125100
Company in Boston, United States
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersBala Cynwyd, PA
- Founded2005
- Websitezafgen.com
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($47.3k this quarter). Holder counts are more reliable. Shares outstanding: 103.9m as of 2026-08-02, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $3.07. Options: 6 managers hold calls ($1.7m notional), 5 hold puts ($3.0m).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 60 |
| Q4 2022 | 49 |
| Q1 2023 | 70 |
| Q2 2023 | 66 |
| Q3 2023 | 66 |
| Q4 2023 | 70 |
| Q1 2024 | 105 |
| Q2 2024 | 108 |
| Q3 2024 | 124 |
| Q4 2024 | 117 |
| Q1 2025 | 104 |
| Q2 2025 | 117 |
| Q3 2025 | 136 |
| Q4 2025 | 136 |
| Q1 2026 | 162 |
| Q2 2026 | 163 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 63 | 43 |
| Q4 2024 | 58 | 60 |
| Q1 2025 | 48 | 58 |
| Q2 2025 | 72 | 41 |
| Q3 2025 | 89 | 34 |
| Q4 2025 | 66 | 63 |
| Q1 2026 | 98 | 56 |
| Q2 2026 | 100 | 70 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $22.7m | $2.1m | 0.09 |
| Q4 2025 | $682.0k | $72.8k | 0.11 |
| Q1 2026 | $5.5m | $1.7m | 0.31 |
| Q2 2026 | $1.7m | $3.0m | 1.82 |
Biggest buyers
| Defilade Capital Management, L.P. | New | +3.7m |
| Blue Owl Capital Holdings LP | Added | +2.0m |
| BlackRock, Inc. | Added | +1.9m |
| AQR CAPITAL MANAGEMENT LLC | Added | +1.6m |
| MARSHALL WACE, LLP | Added | +1.1m |
| RTW INVESTMENTS, LP | Added | +1.1m |
| VANGUARD PORTFOLIO MANAGEMENT LLC | Added | +996.6k |
| CITADEL ADVISORS LLC | Added | +937.7k |
| SPHERA FUNDS MANAGEMENT LTD. | New | +926.0k |
| FMR LLC | Added | +873.8k |
Biggest sellers
| AIGH Capital Management LLC | Sold out | -3.0m |
| MILLENNIUM MANAGEMENT LLC | Reduced | -2.3m |
| Deep Track Capital, LP | Sold out | -1.5m |
| Point72 Asset Management, L.P. | Reduced | -912.6k |
| Soleus Capital Management, L.P. | Reduced | -878.9k |
| D. E. Shaw & Co., Inc. | Sold out | -575.6k |
| Gem Investment Advisors, LLC | Reduced | -534.7k |
| JANE STREET GROUP, LLC | Reduced | -480.3k |
| RENAISSANCE TECHNOLOGIES LLC | Reduced | -442.5k |
| Caption Management, LLC | Reduced | -442.0k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $822.0k269.5k shares |
| GOLDMAN SACHS GROUP INC | Unchanged | $274.5k90.0k shares |
| GROUP ONE TRADING LLC | Reduced | $206.2k67.6k shares |
| SIMPLEX TRADING, LLC | Reduced | $167.8k55.0k shares |
| Blue Owl Capital Holdings LP | Reduced | $145.7k728.6k shares |
| CITADEL ADVISORS LLC | Reduced | $60.7k19.9k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $1.6m518.3k shares |
| CITADEL ADVISORS LLC | Added | $732.6k240.2k shares |
| SIMPLEX TRADING, LLC | Added | $592.6k194.3k shares |
| JANE STREET GROUP, LLC | Reduced | $86.0k28.2k shares |
| GROUP ONE TRADING LLC | Added | $56.1k18.4k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
Flynn James E
13D · may seek influence
-1.4 pts · filed 2026-03-02
Stated purposeItem 4 of the Schedule 13D is hereby amended by adding the following: Each Fund acquired its February 2026 Shares for investment purposes in an underwritten offering conducted by the Company (the "February 2026 Offering") pursuant to the Prospectus Supplement, dated as of February 25, 2026, to the Issuer's Prospectus, dated as of May 24, 2024 (the "February 2026 Offering"). Full filing |
34.4% |
| Blue Owl Capital Holdings LP 13G · institution no change · filed 2026-05-14 | 10.0% |
Fell to 5% or below in the last year: MILLENNIUM MANAGEMENT LLC (3.5%, 2026-04-30), RA CAPITAL MANAGEMENT, L.P. (0.0%, 2026-02-17)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 0 | — | — |
| Q1 2025 | 0 | — | 0 | — | — |
| Q2 2025 | 0 | — | 0 | — | — |
| Q3 2025 | 1 | $30.0m | 0 | — | — |
| Q4 2025 | 0 | — | 0 | — | — |
| Q1 2026 | 4 | $25.5m | 0 | — | — |
| Q2 2026 | 0 | — | 0 | — | — |
| Q3 2026 | 1 | $167.0k | 0 | — | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-07-06 | Hamilton Thomas Edward Director | Bought | $167.0k50.0k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| DEERFIELD MANAGEMENT COMPANY, L.P. 1.13% of their portfolio | 35.6m $108.6m | Unchanged |
| Blue Owl Capital Holdings LP 4.25% of their portfolio | 9.2m $27.9m | Added +2.0m |
| BlackRock, Inc. 0.00% of their portfolio | 5.7m $17.3m | Added +1.9m |
| Defilade Capital Management, L.P. 1.50% of their portfolio | 3.7m $11.2m | New |
| Driehaus Capital Management LLC 0.06% of their portfolio | 3.2m $9.6m | Added +229.0k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 3.0m $9.1m | Added +108.6k |
| RTW INVESTMENTS, LP 0.07% of their portfolio | 2.6m $7.8m | Added +1.1m |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 2.4m $7.2m | Added +1.6m |
| MARSHALL WACE, LLP 0.01% of their portfolio | 2.0m $6.1m | Added +1.1m |
| DAFNA Capital Management LLC 1.17% of their portfolio | 2.0m $6.1m | Reduced -21.0k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 1.8m $5.3m | Added +191.3k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 1.7m $5.1m | Added +570.2k |
| Qube Research & Technologies Ltd 0.01% of their portfolio | 1.6m $5.0m | Added +793.4k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 1.5m $4.4m | Added +937.7k |
| STATE STREET CORP 0.00% of their portfolio | 1.4m $4.3m | Added +500.5k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 1.4m $4.3m | Added +996.6k |
| Woodline Partners LP 0.01% of their portfolio | 1.4m $4.3m | Unchanged |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 1.3m $4.1m | Reduced -2.3m |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 961.1k $2.9m | Added +162.6k |
| FMR LLC 0.00% of their portfolio | 937.4k $2.9m | Added +873.8k |
| SPHERA FUNDS MANAGEMENT LTD. 0.40% of their portfolio | 926.0k $2.8m | New |
| Nuveen, LLC 0.00% of their portfolio | 895.3k $2.7m | Added +220.4k |
| Alyeska Investment Group, L.P. 0.00% of their portfolio | 617.2k $1.9m | Unchanged |
| NORTHERN TRUST CORP 0.00% of their portfolio | 550.3k $1.7m | Added +173.8k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 448.2k $1.4m | Added +158.5k |
| LOS ANGELES CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 399.5k $1.2m | Added +381.5k |
| Hennion & Walsh Asset Management, Inc. 0.03% of their portfolio | 396.7k $1.2m | New |
| SummitTX Capital, L.P. 0.03% of their portfolio | 352.3k $1.1m | Reduced -27.5k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 328.0k $1.0m | Reduced -3.8k |
| Gem Investment Advisors, LLC 0.60% of their portfolio | 319.5k $974.5k | Reduced -534.7k |
| Burkehill Global Management, LP 0.03% of their portfolio | 300.0k $915.0k | Unchanged |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 297.4k $907.2k | Reduced -442.5k |
| ADAR1 Capital Management, LLC 0.04% of their portfolio | 272.7k $831.9k | Added +220.0k |
| Cerity Partners LLC 0.00% of their portfolio | 271.6k $828.3k | Added +23.7k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 236.1k $720.2k | Reduced -239.5k |
| Seven Fleet Capital Management LP 0.12% of their portfolio | 230.9k $704.3k | Reduced -25.7k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 207.0k $631.3k | Added +61.6k |
| IEQ CAPITAL, LLC 0.00% of their portfolio | 203.4k $620.3k | Added +89.3k |
| Caption Management, LLC 0.02% of their portfolio | 193.0k $588.7k | Reduced -442.0k |
| Soleus Capital Management, L.P. 0.02% of their portfolio | 188.1k $573.7k | Reduced -878.9k |
| JACOBS LEVY EQUITY MANAGEMENT, INC 0.00% of their portfolio | 170.6k $520.3k | Added +1.4k |
| Susquehanna Portfolio Strategies, LLC 0.01% of their portfolio | 165.2k $503.7k | New |
| DIADEMA PARTNERS LP 0.16% of their portfolio | 146.6k $447.2k | Reduced -20.0k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 144.4k $440.5k | Added +4.4k |
| UBS Group AG 0.00% of their portfolio | 144.3k $440.2k | Added +114.6k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 138.8k $423.4k | Added +31.5k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 138.2k $421.5k | Added +109.4k |
| Jump Financial, LLC 0.00% of their portfolio | 135.6k $413.6k | Reduced -164.1k |
| Point72 Asset Management, L.P. 0.00% of their portfolio | 134.8k $411.2k | Reduced -912.6k |
| Invesco Ltd. 0.00% of their portfolio | 134.5k $410.2k | Added +114.8k |
| PRUDENTIAL FINANCIAL INC 0.00% of their portfolio | 128.4k $391.7k | Added +95.6k |
| Creative Planning 0.00% of their portfolio | 116.8k $356.2k | Added +51.8k |
| Mariner, LLC 0.00% of their portfolio | 114.4k $349.1k | Added +82.8k |
| Squarepoint Ops LLC 0.00% of their portfolio | 113.5k $346.1k | New |
| Man Group plc 0.00% of their portfolio | 113.0k $344.8k | New |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 108.2k $487.0k | Added +33.7k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 96.4k $294.1k | Added +3.3k |
| FEDERATED HERMES, INC. 0.00% of their portfolio | 90.8k $277.1k | Added +29.5k |
| ExodusPoint Capital Management, LP 0.00% of their portfolio | 90.4k $275.8k | Added +64.0k |
| MORGAN STANLEY 0.00% of their portfolio | 86.9k $264.9k | Reduced -334.0k |
| CARY STREET PARTNERS FINANCIAL LLC 0.01% of their portfolio | 85.0k $259.2k | New |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 73.7k $224.9k | Reduced -480.3k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 71.9k $219.2k | Added +9.2k |
| MERCER GLOBAL ADVISORS INC /ADV 0.00% of their portfolio | 68.9k $210.2k | Added +51.9k |
| Quantbot Technologies LP 0.01% of their portfolio | 68.8k $209.8k | Added +68.4k |
| WEALTH ENHANCEMENT ADVISORY SERVICES, LLC 0.00% of their portfolio | 63.7k $272.6k | Added +30.9k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 62.1k $189.4k | Added +41.9k |
| Connor, Clark & Lunn Investment Management Ltd. 0.00% of their portfolio | 59.8k $182.4k | Reduced -9.3k |
| CANADA PENSION PLAN INVESTMENT BOARD 0.00% of their portfolio | 59.7k $182.1k | Unchanged |
| SIMPLEX TRADING, LLC 0.00% of their portfolio | 58.6k $178.8k | New |
| ACADIAN ASSET MANAGEMENT LLC 0.00% of their portfolio | 57.4k $173.0k | Reduced -2.0k |
| XTX Topco Ltd 0.00% of their portfolio | 55.2k $168.4k | Added +24.3k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 54.6k $167.0k | Added +19.9k |
| CIBC WORLD MARKET INC. 0.00% of their portfolio | 53.0k $161.7k | Unchanged |
| WINTON GROUP Ltd 0.01% of their portfolio | 52.4k $159.8k | New |
| GSA CAPITAL PARTNERS LLP 0.01% of their portfolio | 50.1k $153.0k | New |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 47.6k $145.2k | Added +244 |
| Pale Fire Capital SE 0.01% of their portfolio | 43.0k $131.2k | New |
| Next Level Private LLC 0.02% of their portfolio | 41.7k $127.2k | Unchanged |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 41.2k $125.7k | Unchanged |
| MetLife Investment Management, LLC 0.00% of their portfolio | 39.8k $121.4k | Added +13.1k |
| HighTower Advisors, LLC 0.00% of their portfolio | 37.7k $115.0k | Reduced -767 |
| Persistent Asset Partners Ltd 0.04% of their portfolio | 37.4k $114.0k | Reduced -4.8k |
| CITIGROUP INC 0.00% of their portfolio | 35.6k $108.7k | Reduced -471 |
| Velan Capital Investment Management LP 0.06% of their portfolio | 33.0k $100.7k | Unchanged |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 30.7k $93.5k | Added +7.6k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 27.4k $83.5k | Added +23.8k |
| STRS OHIO 0.00% of their portfolio | 26.5k $80.8k | Added +4.8k |
| AMERICAN CENTURY COMPANIES INC 0.00% of their portfolio | 26.5k $80.7k | Reduced -51.2k |
| BARCLAYS PLC 0.00% of their portfolio | 26.0k $79.2k | Added +9.6k |
| CAPTRUST FINANCIAL ADVISORS 0.00% of their portfolio | 25.2k $76.9k | New |
| COMMONWEALTH EQUITY SERVICES, LLC 0.00% of their portfolio | 23.1k $70.3k | Reduced -1.7k |
| Corient Private Wealth LP 0.00% of their portfolio | 22.7k $69.2k | New |
| Engineers Gate Manager LP 0.00% of their portfolio | 22.6k $68.8k | New |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 21.0k $64.2k | Reduced -30.0k |
| Walleye Trading LLC 0.00% of their portfolio | 20.0k $61.0k | Unchanged |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 19.5k $59.5k | Added +6.1k |
| Brevan Howard Capital Management LP 0.00% of their portfolio | 19.5k $59.5k | New |
| Vanguard Personalized Indexing Management, LLC 0.00% of their portfolio | 18.5k $56.6k | Added +7.4k |
| BRIGHTON JONES LLC 0.00% of their portfolio | 18.5k $56.4k | New |