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Buy Day today: Good (62) Broad market participation · no major macro event
IRON

Disc Medicine Inc.

Healthcare · Biotechnology

69.20$ +0.9% vs. previous close Closing price · As of: Sep 17, 2026

Ownership

Ownership Structure

Who owns Disc Medicine Inc. (IRON)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 85.8% of the shares are freely tradable; institutional investors hold 113.7%.

Institutional ownership ?Share of the stock held by institutional investors (funds, banks, insurers) according to regulatory filings. 113.7%
Insiders ?Share of the stock held by the executives, founders and major shareholders of the company itself. 7.8%
Float ?Share of stock freely tradable on the market — not locked up in the hands of founders, insiders, or major shareholders. 85.8%
Short % of float ?Shares sold short as a percentage of the freely tradable float — high values signal many bets on falling prices. 22.4%
Shares Outstanding ?Total number of shares issued. Price times share count gives market cap. 38Mio.

Largest Shareholders

Institutions

Institutions IRON
Name Stake (%) Shares Change (%) Date
FMR Inc 14.55 5,586,894 +2.5 03/31/2026
RA Capital Management, LLC 6.38 2,450,221 +24.0 03/31/2026
BlackRock Inc 5.92 2,273,831 -0.1 03/31/2026
Wellington Management Company LLP 4.54 1,741,351 +0.3 06/30/2026
State Street Corp 4.42 1,698,244 +43.0 03/31/2026
T. Rowe Price Associates, Inc. 4.04 1,549,350 -8.8 03/31/2026
Atlas Venture Life Science Advisors, LLC 3.94 1,513,875 +0.0 06/30/2026
Vanguard Capital Management, LLC 3.58 1,375,430 +0.0 03/31/2026
JPMorgan Chase & Co 3.57 1,371,480 -13.3 03/31/2026

Funds

Funds IRON
Name Stake (%) Shares Change (%) Date
Strategic Advisers Fidelity US TtlStk 4.97 1,909,438 -0.2 07/31/2026

Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.

Insider holdings

Insider holdings IRON
Person Role Shares Value As of Type
Quisel John D Chief Executive Officer 262,064 18,134,829 $ Sep 15, 2026 direct
Yu Jonathan Yen-Wen Chief Operating Officer 54,324 3,759,221 $ Aug 25, 2026 direct
Khara Rahul Chief Legal Officer 52,324 3,620,821 $ Aug 6, 2026 direct
Bitterman Kevin Director 13,427 929,148 $ Sep 4, 2026 both

Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.

Insiders

Insider Transactions

Insider Transactions
Date Person Role Type Shares Price Value
Sep 15, 2026 Quisel John D Chief Executive Officer Other 36,000 1.01 36,360
Sep 11, 2026 Bitterman Kevin Director Sell 27,136 70.11 1,902,505
Sep 11, 2026 Bitterman Kevin Director Other 10,000 50.86 508,600
Sep 11, 2026 Bitterman Kevin Director Other 7,136 45.69 326,044
Sep 4, 2026 Bitterman Kevin Director Sell 18 79.96 1,439
Sep 4, 2026 Bitterman Kevin Director Sell 759 79.96 60,690
Sep 4, 2026 Bitterman Kevin Director Sell 912 79.96 72,924
Sep 3, 2026 Bitterman Kevin Director Sell 54 79.98 4,319
Sep 3, 2026 Bitterman Kevin Director Sell 2,339 79.98 187,073
Sep 3, 2026 Bitterman Kevin Director Sell 2,810 79.98 224,744
Sep 2, 2026 Bitterman Kevin Director Sell 2 80.98 162
Sep 2, 2026 Bitterman Kevin Director Sell 9 80.98 729
Sep 2, 2026 Bitterman Kevin Director Sell 10 80.98 810
Sep 2, 2026 Bitterman Kevin Director Sell 511 80.17 40,967
Sep 2, 2026 Bitterman Kevin Director Sell 22,090 80.17 1,770,955
Sep 2, 2026 Bitterman Kevin Director Sell 26,542 80.17 2,127,872
Sep 1, 2026 Bitterman Kevin Director Sell 1 79.95 80
Sep 1, 2026 Bitterman Kevin Director Sell 58 79.95 4,637
Sep 1, 2026 Bitterman Kevin Director Sell 70 79.95 5,597
Aug 25, 2026 Yu Jonathan Yen-Wen Chief Operating Officer Sell 8,796 83.12 731,092
Aug 25, 2026 Yu Jonathan Yen-Wen Chief Operating Officer Other 8,796 13.50 118,746
Aug 24, 2026 Yu Jonathan Yen-Wen Chief Operating Officer Sell 300 82.53 24,760
Aug 24, 2026 Yu Jonathan Yen-Wen Chief Operating Officer Other 300 13.50 4,050
Aug 17, 2026 Quisel John D Chief Executive Officer Sell 11,888 79.84 949,162
Aug 17, 2026 Quisel John D Chief Executive Officer Sell 12,712 79.20 1,006,729
Aug 17, 2026 Quisel John D Chief Executive Officer Sell 8,400 78.11 656,091
Aug 17, 2026 Quisel John D Chief Executive Officer Other 33,000 13.50 445,500
Aug 12, 2026 Yu Jonathan Yen-Wen Chief Operating Officer Sell 804 82.64 66,445
Aug 12, 2026 Yu Jonathan Yen-Wen Chief Operating Officer Other 804 13.50 10,854
Aug 6, 2026 Khara Rahul Chief Legal Officer Sell 5,000 80.00 400,000
Aug 6, 2026 Khara Rahul Chief Legal Officer Other 5,000 14.69 73,450
Jul 13, 2026 Quisel John D Chief Executive Officer Sell 6,400 76.05 486,733
Jul 13, 2026 Quisel John D Chief Executive Officer Sell 16,896 74.95 1,266,303
Jul 13, 2026 Quisel John D Chief Executive Officer Sell 9,704 74.27 720,744
Jul 13, 2026 Quisel John D Chief Executive Officer Other 7,416 13.50 100,116
Jul 13, 2026 Quisel John D Chief Executive Officer Other 25,584 9.86 252,258
Jul 7, 2026 Yu Jonathan Yen-Wen Chief Operating Officer Sell 100 82.50 8,250
Jul 7, 2026 Yu Jonathan Yen-Wen Chief Operating Officer Other 100 13.50 1,350

Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →

Data as of: September 17, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)

Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.

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