Larimar Therapeutics, Inc.
US ˙ NasdaqGM ˙ US5171251003

SecurityLRMR / Larimar Therapeutics, Inc.
InstitutionCaption Management, LLC
Latest Disclosed Ownership635,024 shares
Latest Disclosed Value $ 2,857,608
Caption Management, LLC ownership in LRMR / Larimar Therapeutics, Inc.

On May 15, 2026 - Caption Management, LLC filed a 13F-HR form disclosing ownership of 635,024 shares of Larimar Therapeutics, Inc. (US:LRMR) valued at $2,857,608 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 415,294 shares of Larimar Therapeutics, Inc.. This represents a change in shares of 52.91% during the quarter. The current value of the position is $2,032,077 USD.

Caption Management, LLC 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 164,200 of underlying shares valued at $738,900 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)
2026-05-15 2026-03-31 13F LARIMAR THERAPEUTICS COM 517125100 635,024 219,730 52.91 2,858 80.59 0.0167
2026-02-17 2025-12-31 13F LARIMAR THERAPEUTICS COM 517125100 415,294 -897,058 -68.35 1,582 -62.67 0.0109
2025-11-14 2025-09-30 13F LARIMAR THERAPEUTICS COM 517125100 1,312,352 623,062 90.39 4,239 112.75 0.0331
2025-08-14 2025-06-30 13F LARIMAR THERAPEUTICS COM 517125100 689,290 689,290 1,992 0.0220
2024-08-14 2024-06-30 13F LARIMAR THERAPEUTICS COM 517125100 0 -142,900 -100.00 0 -100.00
2024-05-15 2024-03-31 13F LARIMAR THERAPEUTICS COM 517125100 142,900 142,900 1,085 0.0165
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
(%)
2026-05-15 2026-03-31 13F LARIMAR THERAPEUTICS COM Call 164,200 739 n/a n/a n/a
2026-02-17 2025-12-31 13F LARIMAR THERAPEUTICS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-11-14 2025-09-30 13F LARIMAR THERAPEUTICS COM Call 1,539,700 14.51 4,973 28.01 n/a n/a n/a
2025-08-14 2025-06-30 13F LARIMAR THERAPEUTICS COM Call 1,344,600 3,886 n/a n/a n/a
2025-05-15 2025-03-31 13F LARIMAR THERAPEUTICS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-14 2024-12-31 13F LARIMAR THERAPEUTICS COM Call 25,000 97 n/a n/a n/a
2024-08-14 2024-06-30 13F LARIMAR THERAPEUTICS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2024-05-15 2024-03-31 13F LARIMAR THERAPEUTICS COM Call 266,400 2,022 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.