Lexeo Therapeutics, Inc.
US ˙ NasdaqGM ˙ US52886X1072

SecurityLXEO / Lexeo Therapeutics, Inc.
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership5,498,219 shares
Ownership 7.40%
Citadel Advisors Llc ownership in LXEO / Lexeo Therapeutics, Inc.

2026-02-17 - Citadel Advisors Llc has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 5,498,219 shares of Lexeo Therapeutics, Inc. (US:LXEO). This represents 7.4 percent ownership of the company. In their previous filing dated 2025-08-14 , Citadel Advisors Llc had reported owning 5,334,112 shares, indicating an increase of 3.08 percent.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (LXEO) in the form of stock options. The firm currently holds call options representing 10,700 of underlying shares valued at $61,418 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: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File
Date
Effective
Date
Form Prev
Shares
Latest
Shares
ΔShares
(Percent)
Ownership
(Percent)
ΔOwnership
(Percent)
2026-02-17 2026-02-17 13G/A 5,334,112 5,498,219 3.08 7.40 -22.92
2025-08-14 2025-08-14 13G/A 5,334,112 9.60 23.08
2024-02-14 2024-02-14 13G/A 7.80 -6.02
2023-11-17 2023-11-17 13G 8.30

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

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.

LXEO / Lexeo 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 LEXEO THERAPEUTICS COM 52886X107 3,834,999 60,682 1.61 22,013 -41.27 0.0036
2026-02-17 2025-12-31 13F LEXEO THERAPEUTICS COM 52886X107 3,774,317 55,274 1.49 37,479 51.77 0.0056
2025-11-14 2025-09-30 13F LEXEO THERAPEUTICS COM 52886X107 3,719,043 111,076 3.08 24,694 70.26 0.0038
2025-08-14 2025-06-30 13F LEXEO THERAPEUTICS COM 52886X107 3,607,967 884,604 32.48 14,504 53.48 0.0025
2025-05-15 2025-03-31 13F LEXEO THERAPEUTICS COM 52886X107 2,723,363 0 0.00 9,450 -47.26 0.0018
2025-02-14 2024-12-31 13F LEXEO THERAPEUTICS COM 52886X107 2,723,363 0 0.00 17,920 -27.21 0.0031
2024-11-14 2024-09-30 13F LEXEO THERAPEUTICS COM 52886X107 2,723,363 164,752 6.44 24,619 -40.01 0.0047
2024-08-14 2024-06-30 13F LEXEO THERAPEUTICS COM 52886X107 2,558,611 55,630 2.22 41,040 5.54 0.0083
2024-05-15 2024-03-31 13F LEXEO THERAPEUTICS COM 52886X107 2,502,981 418,736 20.09 38,884 39.02 0.0075
2024-02-14 2023-12-31 13F LEXEO THERAPEUTICS COM 52886X107 2,084,245 2,084,245 27,971 0.0056
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 LEXEO THERAPEUTICS COM Call 10,700 61 n/a n/a n/a
2025-08-14 2025-06-30 13F LEXEO THERAPEUTICS COM Call 0 -100.00 0 n/a n/a n/a
2025-05-15 2025-03-31 13F LEXEO THERAPEUTICS COM Call 100 0 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
(%)
2025-08-14 2025-06-30 13F LEXEO THERAPEUTICS COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-05-15 2025-03-31 13F LEXEO THERAPEUTICS COM Put 12,800 44 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.