Larimar Therapeutics, Inc.
US ˙ NasdaqGM ˙ US5171251003

SecurityLRMR / Larimar Therapeutics, Inc.
InstitutionGroup One Trading, L.p.
Latest Disclosed Ownership0 shares
Latest Disclosed Value $ 0
Group One Trading, L.p. ownership in LRMR / Larimar Therapeutics, Inc.

On February 11, 2026 - Group One Trading, L.p. filed a 13F-HR form disclosing ownership of 0 shares of Larimar Therapeutics, Inc. (US:LRMR) valued at $0 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 12, 2025 disclosing 133,701 shares of Larimar Therapeutics, Inc.. This represents a change in shares of -100.00% during the quarter. The current value of the position is $0 USD.

Group One Trading, L.p. has a history of taking positions in derivatives of the underlying security (LRMR) in the form of stock options. The firm currently holds call options representing 23,000 of underlying shares valued at $87,630 USD and put options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

LRMR / Larimar Therapeutics, Inc. Historical Put/Call Ratio
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)
2026-02-11 2025-12-31 13F LARIMAR THERAPEUTICS COM 517125100 0 -133,701 -100.00 0 -100.00
2025-11-12 2025-09-30 13F LARIMAR THERAPEUTICS COM 517125100 133,701 85,476 177.24 432 210.07 0.0008
2025-08-14 2025-06-30 13F LARIMAR THERAPEUTICS COM 517125100 48,225 47,100 4,186.67 139 6,850.00 0.0003
2025-05-14 2025-03-31 13F LARIMAR THERAPEUTICS COM 517125100 1,125 -12,228 -91.57 2 -96.08 0.0000
2025-05-14 2024-12-31 13F/A-1 LARIMAR THERAPEUTICS COM 517125100 13,353 9,273 227.28 52 96.15 0.0001
2025-02-14 2024-12-31 13F LARIMAR THERAPEUTICS COM 517125100 13,353 9,273 52 0.0001
2024-11-14 2024-09-30 13F LARIMAR THERAPEUTICS COM 517125100 4,080 4,080 27 0.0001
2024-08-14 2024-06-30 13F LARIMAR THERAPEUTICS COM 517125100 0 -8,638 -100.00 0 -100.00
2024-05-10 2024-03-31 13F LARIMAR THERAPEUTICS COM 517125100 8,638 8,638 66 0.0003
2023-11-09 2023-09-30 13F LARIMAR THERAPEUTICS COM 517125100 0 -500 -100.00 0 -100.00
2023-08-09 2023-06-30 13F LARIMAR THERAPEUTICS COM 517125100 500 500 2 0.0000
2022-02-11 2021-12-31 13F LARIMAR THERAPEUTICS COM 517125100 0 -1,000 -100.00 0 -100.00
2021-11-12 2021-09-30 13F LARIMAR THERAPEUTICS COM 517125100 1,000 1,000 12 0.0000
2021-08-10 2021-06-30 13F LARIMAR THERAPEUTICS COM 517125100 0 -416 -100.00 0 -100.00
2021-05-12 2021-03-31 13F LARIMAR THERAPEUTICS COM 517125100 416 0 0.00 6 -33.33 0.0000
2021-02-10 2020-12-31 13F LARIMAR THERAPEUTICS COM 517125100 416 0 0.00 9 50.00 0.0000
2020-11-12 2020-09-30 13F LARIMAR THERAPEUTICS COM 517125100 416 0 0.00 6 20.00 0.0000
2020-08-13 2020-06-30 13F LARIMAR THERAPEUTICS COM 517125100 416 116 38.67 5 -16.67 0.0000
2020-05-13 2020-03-31 13F ZAFGEN COM 98885E103 300 0 0.00 0 -100.00 0.0000
2020-02-10 2019-12-31 13F ZAFGEN COM 98885E103 300 -1,100 -78.57 0 -100.00
2019-08-09 2019-06-30 13F ZAFGEN COM 98885E103 1,400 -3,672 -72.40 2 -85.71 0.0000
2019-05-14 2019-03-31 13F/A-1 ZAFGEN COM 98885E103 5,072 5,072 262.29 14 600.00 0.0002
2019-05-13 2019-03-31 13F ZAFGEN COM 98885E103 5,072 5,072 14
2018-11-08 2018-09-30 13F ZAFGEN COM 98885E103 0 -3,002 -100.00 0 -100.00
2018-08-13 2018-06-30 13F ZAFGEN COM 98885E103 3,002 2,600 646.77 31 933.33 0.0003
2018-05-16 2018-03-31 13F/A-1 ZAFGEN COM 98885E103 402 -3,424 -89.49 3 -83.33 0.0000
2018-05-10 2018-03-31 13F ZAFGEN COM 98885E103 402 -3,424 3
2018-02-09 2017-12-31 13F ZAFGEN COM 98885E103 3,826 3,826 851.74 18 500.00 0.0001
2017-11-14 2017-09-30 13F ZAFGEN COM 98885E103 0 -4,826 -100.00 0 -100.00
2017-08-14 2017-06-30 13F ZAFGEN COM 98885E103 4,826 2,179 82.32 17 41.67 0.0002
2017-05-10 2017-03-31 13F ZAFGEN COM 98885E103 2,647 -16,071 -85.86 12 -80.00 0.0001
2017-02-15 2016-12-31 13F ZAFGEN COM 98885E103 18,718 -3,000 -13.81 60 -16.67 0.0006
2016-11-14 2016-09-30 13F ZAFGEN COM 98885E103 21,718 21,576 15,194.37 72 7,100.00 0.0008
2016-08-12 2016-06-30 13F ZAFGEN COM 98885E103 142 -3,018 -95.51 1 -95.24 0.0000
2016-05-12 2016-03-31 13F ZAFGEN COM 98885E103 3,160 -5,550 -63.72 21 -61.82 0.0003
2016-02-11 2015-12-31 13F ZAFGEN COM 98885E103 8,710 234 2.76 55 -79.70 0.0007
2015-11-20 2015-09-30 13F/A-1 ZAFGEN COM 98885E103 8,476 8,476 271 0.0037
2015-11-06 2015-09-30 13F ZAFGEN COM 98885E103 8,476 271 0.0037
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-02-11 2025-12-31 13F LARIMAR THERAPEUTICS COM Call 23,000 -96.12 88 -95.46 n/a n/a n/a
2025-11-12 2025-09-30 13F LARIMAR THERAPEUTICS COM Call 593,400 777.81 1,917 882.56 n/a n/a n/a
2025-08-14 2025-06-30 13F LARIMAR THERAPEUTICS COM Call 67,600 13,420.00 195 19,400.00 n/a n/a n/a
2025-05-14 2025-03-31 13F LARIMAR THERAPEUTICS COM Call 500 -98.27 1 -99.10 n/a n/a n/a
2025-05-14 2024-12-31 13F/A LARIMAR THERAPEUTICS COM Call 28,900 224.72 112 91.38 n/a n/a n/a
2025-02-14 2024-12-31 13F LARIMAR THERAPEUTICS COM Call 28,900 112 n/a n/a n/a
2024-11-14 2024-09-30 13F LARIMAR THERAPEUTICS COM Call 8,900 -31.01 58 -37.63 n/a n/a n/a
2024-08-14 2024-06-30 13F LARIMAR THERAPEUTICS COM Call 12,900 200.00 94 190.63 n/a n/a n/a
2024-05-10 2024-03-31 13F LARIMAR THERAPEUTICS COM Call 4,300 33 n/a n/a n/a
2024-02-14 2023-12-31 13F LARIMAR THERAPEUTICS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2023-11-09 2023-09-30 13F LARIMAR THERAPEUTICS COM Call 2,000 400.00 8 600.00 n/a n/a n/a
2023-08-09 2023-06-30 13F LARIMAR THERAPEUTICS COM Call 400 1 n/a n/a n/a
2023-02-09 2022-12-31 13F LARIMAR THERAPEUTICS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-11-09 2022-09-30 13F LARIMAR THERAPEUTICS COM Call 500 -50.00 2 0.00 n/a n/a n/a
2022-08-11 2022-06-30 13F LARIMAR THERAPEUTICS COM Call 1,000 -95.41 2 -97.73 n/a n/a n/a
2022-05-12 2022-03-31 13F LARIMAR THERAPEUTICS COM Call 21,800 88 n/a n/a n/a
2022-02-11 2021-12-31 13F LARIMAR THERAPEUTICS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-11-12 2021-09-30 13F LARIMAR THERAPEUTICS COM Call 2,000 900.00 23 1,050.00 n/a n/a n/a
2021-08-10 2021-06-30 13F LARIMAR THERAPEUTICS COM Call 200 2 n/a n/a n/a
2020-08-13 2020-06-30 13F ZAFGEN COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-05-13 2020-03-31 13F ZAFGEN COM Call 2,500 2 n/a n/a n/a
2018-11-08 2018-09-30 13F ZAFGEN COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-08-13 2018-06-30 13F ZAFGEN COM Call 3,100 32 n/a n/a n/a
2018-05-16 2018-03-31 13F/A ZAFGEN COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-02-09 2017-12-31 13F ZAFGEN COM Call 14,400 7.46 67 42.55 n/a n/a n/a
2017-11-15 2017-09-30 13F ZAFGEN COM Call 13,400 8.06 47 6.82 n/a n/a n/a
2017-08-14 2017-06-30 13F ZAFGEN COM Call 12,400 -7.46 44 -6.38 n/a n/a n/a
2017-05-10 2017-03-31 13F ZAFGEN COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-02-15 2016-12-31 13F ZAFGEN COM Call 15,700 -17.37 50 -20.63 n/a n/a n/a
2016-11-14 2016-09-30 13F ZAFGEN COM Call 19,000 578.57 63 270.59 n/a n/a n/a
2016-08-12 2016-06-30 13F ZAFGEN COM Call 2,800 -96.38 17 -96.71 n/a n/a n/a
2016-05-12 2016-03-31 13F ZAFGEN COM Call 77,300 -38.01 516 -34.18 n/a n/a n/a
2016-02-11 2015-12-31 13F ZAFGEN COM Call 124,700 41,466.67 784 7,740.00 n/a n/a n/a
2015-11-20 2015-09-30 13F/A ZAFGEN COM Call 300 -97.20 10 -97.30 n/a n/a n/a
2015-11-06 2015-09-30 13F ZAFGEN COM Call 300 10 n/a n/a n/a
2015-08-11 2015-06-30 13F ZAFGEN COM Call 10,700 371 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-02-11 2025-12-31 13F LARIMAR THERAPEUTICS COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-11-12 2025-09-30 13F LARIMAR THERAPEUTICS COM Put 500 -85.71 2 -90.00 n/a n/a n/a
2025-08-14 2025-06-30 13F LARIMAR THERAPEUTICS COM Put 3,500 59.09 10 150.00 n/a n/a n/a
2025-05-14 2025-03-31 13F LARIMAR THERAPEUTICS COM Put 2,200 -94.67 5 -97.48 n/a n/a n/a
2025-05-14 2024-12-31 13F/A LARIMAR THERAPEUTICS COM Put 41,300 -11.75 160 -48.04 n/a n/a n/a
2025-02-14 2024-12-31 13F LARIMAR THERAPEUTICS COM Put 41,300 160 n/a n/a n/a
2024-11-14 2024-09-30 13F LARIMAR THERAPEUTICS COM Put 46,800 307 n/a n/a n/a
2024-08-14 2024-06-30 13F LARIMAR THERAPEUTICS COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2024-05-10 2024-03-31 13F LARIMAR THERAPEUTICS COM Put 37,600 285 n/a n/a n/a
2023-11-09 2023-09-30 13F LARIMAR THERAPEUTICS COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2023-08-09 2023-06-30 13F LARIMAR THERAPEUTICS COM Put 500 2 n/a n/a n/a
2022-02-11 2021-12-31 13F LARIMAR THERAPEUTICS COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-11-12 2021-09-30 13F LARIMAR THERAPEUTICS COM Put 1,000 0.00 12 20.00 n/a n/a n/a
2021-08-10 2021-06-30 13F LARIMAR THERAPEUTICS COM Put 1,000 10 n/a n/a n/a
2020-08-13 2020-06-30 13F ZAFGEN COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-05-13 2020-03-31 13F ZAFGEN COM Put 300 0.00 0 n/a n/a n/a
2020-02-10 2019-12-31 13F ZAFGEN COM Put 300 -93.18 0 -100.00 n/a n/a n/a
2019-08-09 2019-06-30 13F ZAFGEN COM Put 4,400 0.00 5 -58.33 n/a n/a n/a
2019-05-14 2019-03-31 13F/A ZAFGEN COM Put 4,400 0.00 12 140.00 n/a n/a n/a
2019-05-13 2019-03-31 13F ZAFGEN COM Put 4,400 12 n/a n/a n/a
2018-11-08 2018-09-30 13F ZAFGEN COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2018-08-13 2018-06-30 13F ZAFGEN COM Put 12,800 -4.48 131 31.00 n/a n/a n/a
2018-05-16 2018-03-31 13F/A ZAFGEN COM Put 13,400 2,133.33 100 3,233.33 n/a n/a n/a
2018-05-10 2018-03-31 13F ZAFGEN COM Put 13,400 100 n/a n/a n/a
2018-02-09 2017-12-31 13F ZAFGEN COM Put 600 -70.00 3 -57.14 n/a n/a n/a
2017-11-15 2017-09-30 13F ZAFGEN COM Put 2,000 -71.43 7 -72.00 n/a n/a n/a
2017-08-14 2017-06-30 13F ZAFGEN COM Put 7,000 40.00 25 8.70 n/a n/a n/a
2017-05-10 2017-03-31 13F ZAFGEN COM Put 5,000 -96.20 23 -94.50 n/a n/a n/a
2017-02-15 2016-12-31 13F ZAFGEN COM Put 131,600 -3.66 418 -7.52 n/a n/a n/a
2016-11-14 2016-09-30 13F ZAFGEN COM Put 136,600 7,935.29 452 4,420.00 n/a n/a n/a
2016-08-12 2016-06-30 13F ZAFGEN COM Put 1,700 -91.37 10 -92.42 n/a n/a n/a
2016-05-12 2016-03-31 13F ZAFGEN COM Put 19,700 -36.04 132 -31.96 n/a n/a n/a
2016-02-11 2015-12-31 13F ZAFGEN COM Put 30,800 135.11 194 -53.70 n/a n/a n/a
2015-11-20 2015-09-30 13F/A ZAFGEN COM Put 13,100 419 n/a n/a n/a
2015-11-06 2015-09-30 13F ZAFGEN COM Put 13,100 419 n/a n/a n/a
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.