Larimar Therapeutics, Inc.
US ˙ NasdaqGM ˙ US5171251003

SecurityLRMR / Larimar Therapeutics, Inc.
InstitutionD. E. Shaw & Co., Inc.
ManagerDE Shaw
Latest Disclosed Ownership575,624 shares
Latest Disclosed Value $ 2,590,308
D. E. Shaw & Co., Inc. reports 31.60% increase in ownership of LRMR / Larimar Therapeutics, Inc.

On May 15, 2026 - D. E. Shaw & Co., Inc. filed a 13F-HR form disclosing ownership of 575,624 shares of Larimar Therapeutics, Inc. (US:LRMR) valued at $2,590,308 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 437,399 shares of Larimar Therapeutics, Inc.. This represents a change in shares of 31.60% during the quarter. The current value of the position is $1,841,997 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F LARIMAR THERAPEUTICS COM 517125100 575,624 138,225 31.60 2,590 55.46 0.0016
2026-02-17 2025-12-31 13F LARIMAR THERAPEUTICS COM 517125100 437,399 437,399 1,666 0.0009
2025-02-14 2024-12-31 13F LARIMAR THERAPEUTICS COM 517125100 0 -16,122 -100.00 0 -100.00
2024-11-14 2024-09-30 13F LARIMAR THERAPEUTICS COM 517125100 16,122 16,122 106 0.0001
2020-02-14 2019-12-31 13F ZAFGEN COM 98885E103 0 -243,858 -100.00 0 -100.00
2019-11-14 2019-09-30 13F ZAFGEN COM 98885E103 243,858 142,674 141.00 180 48.76 0.0002
2019-08-14 2019-06-30 13F ZAFGEN COM 98885E103 101,184 -30,629 -23.24 121 -66.48 0.0002
2019-05-15 2019-03-31 13F ZAFGEN COM 98885E103 131,813 -17,222 -11.56 361 -51.08 0.0005
2019-02-14 2018-12-31 13F ZAFGEN COM 98885E103 149,035 -113,857 -43.31 738 -75.99 0.0010
2018-11-14 2018-09-30 13F ZAFGEN COM 98885E103 262,892 -85,264 -24.49 3,074 -13.68 0.0037
2018-08-14 2018-06-30 13F ZAFGEN COM 98885E103 348,156 -45,349 -11.52 3,561 21.45 0.0046
2018-05-15 2018-03-31 13F ZAFGEN COM 98885E103 393,505 -39,005 -9.02 2,932 46.67 0.0040
2018-02-14 2017-12-31 13F ZAFGEN COM 98885E103 432,510 -40,125 -8.49 1,999 20.13 0.0028
2017-11-14 2017-09-30 13F ZAFGEN COM 98885E103 472,635 28,890 6.51 1,664 6.80 0.0026
2017-08-14 2017-06-30 13F ZAFGEN COM 98885E103 443,745 -63,943 -12.59 1,558 -34.15 0.0026
2017-05-15 2017-03-31 13F ZAFGEN COM 98885E103 507,688 55,256 12.21 2,366 64.42 0.0042
2017-02-14 2016-12-31 13F ZAFGEN COM 98885E103 452,432 78,147 20.88 1,439 16.14 0.0024
2016-11-14 2016-09-30 13F ZAFGEN COM 98885E103 374,285 -46,020 -10.95 1,239 -50.79 0.0022
2016-08-15 2016-06-30 13F ZAFGEN COM 98885E103 420,305 84,838 25.29 2,518 12.36 0.0046
2016-05-16 2016-03-31 13F ZAFGEN COM 98885E103 335,467 335,467 0.00 2,241 0.0040
2015-11-16 2015-09-30 13F ZAFGEN COM 98885E103 0 -8,768 -100.00 0 -100.00
2015-08-14 2015-06-30 13F ZAFGEN COM 98885E103 8,768 8,768 304 0.0005
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.