Disc Medicine, Inc.
US ˙ NasdaqGM ˙ US2546041011

SecurityIRON / Disc Medicine, Inc.
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership97,930 shares
Latest Disclosed Value $ 6,261,644
Citadel Advisors Llc ownership in IRON / Disc Medicine, Inc.

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 97,930 shares of Disc Medicine, Inc. (US:IRON) valued at $6,261,644 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 100,395 shares of Disc Medicine, Inc.. This represents a change in shares of -2.46% during the quarter. The current value of the position is $6,561,310 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (IRON) in the form of stock options. The firm currently holds call options representing 12,300 of underlying shares valued at $786,462 USD and put options representing 20,900 of underlying shares valued at $1,336,346 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.

IRON / Disc Medicine, 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 DISC MEDICINE COM 254604101 97,930 -2,465 -2.46 6,262 -21.46 0.0009
2026-02-17 2025-12-31 13F DISC MEDICINE COM 254604101 100,395 50,001 99.22 7,972 139.40 0.0012
2025-11-14 2025-09-30 13F DISC MEDICINE COM 254604101 50,394 50,394 3,330 0.0005
2025-08-14 2025-06-30 13F DISC MEDICINE COM 254604101 0 -62,214 -100.00 0 -100.00
2025-05-15 2025-03-31 13F DISC MEDICINE COM 254604101 62,214 -529,057 -89.48 3,088 -91.76 0.0006
2025-02-14 2024-12-31 13F DISC MEDICINE COM 254604101 591,271 180,247 43.85 37,487 85.60 0.0065
2024-11-14 2024-09-30 13F DISC MEDICINE COM 254604101 411,024 89,503 27.84 20,198 39.39 0.0039
2024-08-14 2024-06-30 13F DISC MEDICINE COM 254604101 321,521 -4,203 -1.29 14,491 -28.55 0.0029
2024-05-15 2024-03-31 13F DISC MEDICINE COM 254604101 325,724 137,800 73.33 20,280 86.83 0.0039
2024-02-14 2023-12-31 13F DISC MEDICINE COM 254604101 187,924 -122,507 -39.46 10,854 -25.58 0.0022
2023-11-14 2023-09-30 13F DISC MEDICINE COM 254604101 310,431 -340,889 -52.34 14,584 -49.57 0.0031
2023-08-14 2023-06-30 13F DISC MEDICINE COM 254604101 651,320 480,082 280.36 28,919 697.08 0.0060
2023-05-15 2023-03-31 13F DISC MEDICINE COM 254604101 171,238 115,560 207.55 3,629 227.73 0.0008
2023-02-14 2022-12-31 13F DISC MEDICINE COM 254604101 55,678 55,678 1,107 0.0003
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 DISC MEDICINE COM Call 12,300 786 n/a n/a n/a
2025-08-14 2025-06-30 13F DISC MEDICINE COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-05-15 2025-03-31 13F DISC MEDICINE COM Call 900 -92.91 45 -94.53 n/a n/a n/a
2025-02-14 2024-12-31 13F DISC MEDICINE COM Call 12,700 1,170.00 805 1,542.86 n/a n/a n/a
2024-11-14 2024-09-30 13F DISC MEDICINE COM Call 1,000 -83.05 49 -81.51 n/a n/a n/a
2024-08-14 2024-06-30 13F DISC MEDICINE COM Call 5,900 -87.50 266 -90.98 n/a n/a n/a
2024-05-15 2024-03-31 13F DISC MEDICINE COM Call 47,200 193.17 2,939 216.25 n/a n/a n/a
2024-02-14 2023-12-31 13F DISC MEDICINE COM Call 16,100 930 n/a n/a n/a
2023-05-15 2023-03-31 13F DISC MEDICINE COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2023-02-14 2022-12-31 13F DISC MEDICINE COM Call 970 19 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
(%)
2026-05-15 2026-03-31 13F DISC MEDICINE COM Put 20,900 1,336 n/a n/a n/a
2026-02-17 2025-12-31 13F DISC MEDICINE COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-11-14 2025-09-30 13F DISC MEDICINE COM Put 3,900 -80.98 258 -76.31 n/a n/a n/a
2025-08-14 2025-06-30 13F DISC MEDICINE COM Put 20,500 4,000.00 1,086 4,420.83 n/a n/a n/a
2025-05-15 2025-03-31 13F DISC MEDICINE COM Put 500 25.00 25 -4.00 n/a n/a n/a
2025-02-14 2024-12-31 13F DISC MEDICINE COM Put 400 -86.67 25 -82.99 n/a n/a n/a
2024-11-14 2024-09-30 13F DISC MEDICINE COM Put 3,000 -73.68 147 -71.35 n/a n/a n/a
2024-08-14 2024-06-30 13F DISC MEDICINE COM Put 11,400 -19.72 514 -41.97 n/a n/a n/a
2024-05-15 2024-03-31 13F DISC MEDICINE COM Put 14,200 610.00 884 668.70 n/a n/a n/a
2024-02-14 2023-12-31 13F DISC MEDICINE COM Put 2,000 116 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.