DISC MEDICINE INC IRON
COM · Common Stock · CUSIP 254604101
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersWatertown, MA
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($429.8k this quarter). Holder counts are more reliable. Shares outstanding: 38.2m as of 2026-04-30, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $63.75. Options: 5 managers hold calls ($23.3m notional), 4 hold puts ($5.0m).
Trends to Q1 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q4 2022 | 35 |
| Q1 2023 | 46 |
| Q2 2023 | 91 |
| Q3 2023 | 92 |
| Q4 2023 | 113 |
| Q1 2024 | 132 |
| Q2 2024 | 123 |
| Q3 2024 | 134 |
| Q4 2024 | 154 |
| Q1 2025 | 159 |
| Q2 2025 | 153 |
| Q3 2025 | 168 |
| Q4 2025 | 198 |
| Q1 2026 | 204 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q2 2024 | 82 | 67 |
| Q3 2024 | 80 | 40 |
| Q4 2024 | 79 | 60 |
| Q1 2025 | 98 | 52 |
| Q2 2025 | 92 | 69 |
| Q3 2025 | 88 | 52 |
| Q4 2025 | 122 | 59 |
| Q1 2026 | 120 | 82 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2025 | $23.4m | $1.1m | 0.05 |
| Q3 2025 | $3.1m | $871.3k | 0.28 |
| Q4 2025 | $2.5m | $9.4m | 3.73 |
| Q1 2026 | $23.3m | $5.0m | 0.21 |
Biggest buyers
| TCG Crossover Management, LLC | New | +1.3m |
| BVF INC/IL | Added | +622.3k |
| STATE STREET CORP | Added | +510.3k |
| RA CAPITAL MANAGEMENT, L.P. | Added | +474.1k |
| Bellevue Group AG | New | +459.3k |
| Octagon Capital Advisors LP | New | +270.0k |
| Opaleye Management Inc. | Added | +221.0k |
| WELLINGTON MANAGEMENT GROUP LLP | Added | +217.1k |
| SILVERARC CAPITAL MANAGEMENT, LLC | New | +196.0k |
| Assenagon Asset Management S.A. | Added | +188.4k |
Biggest sellers
| First Light Asset Management, LLC | Sold out | -523.2k |
| PERCEPTIVE ADVISORS LLC | Sold out | -450.7k |
| GREAT POINT PARTNERS LLC | Sold out | -250.0k |
| Balyasny Asset Management L.P. | Sold out | -221.8k |
| JPMORGAN CHASE & CO | Reduced | -209.6k |
| TimesSquare Capital Management, LLC | Sold out | -187.8k |
| Checkpoint Capital L.P. | Reduced | -166.3k |
| First Turn Management, LLC | Sold out | -153.2k |
| PRICE T ROWE ASSOCIATES INC /MD/ | Reduced | -148.7k |
| GOLDMAN SACHS GROUP INC | Reduced | -114.4k |
Biggest calls
| Caption Management, LLC | New | $19.2m300.0k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $2.3m36.7k shares |
| CITADEL ADVISORS LLC | New | $786.5k12.3k shares |
| SIMPLEX TRADING, LLC | Added | $594.6k9.3k shares |
| JANE STREET GROUP, LLC | Reduced | $377.2k5.9k shares |
Biggest puts
| Nantahala Capital Management, LLC | New | $2.6m41.0k shares |
| CITADEL ADVISORS LLC | New | $1.3m20.9k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $1.0m16.2k shares |
| SIMPLEX TRADING, LLC | Reduced | $12.8k200 shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| FMR LLC 13G · institution -1.3 pts · filed 2026-08-06 | 12.8% |
| AI DMI LLC 13D · may seek influence -1.4 pts · filed 2026-10-26 | 6.6% |
| RA CAPITAL MANAGEMENT, L.P. 13G · passive investor new · filed 2026-01-07 | 5.9% |
Fell to 5% or below in the last year: Atlas Venture Fund X, L.P. (2.2%, 2025-12-17)
Insider purchases and sales in Q1 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q2 2024 | 3 | $11.0m | 1 | $157.8k | $157.8k |
| Q3 2024 | 0 | — | 2 | $262.1k | $262.1k |
| Q4 2024 | 0 | — | 3 | $4.9m | $4.9m |
| Q1 2025 | 0 | — | 8 | $21.9m | $887.2k |
| Q2 2025 | 0 | — | 2 | $693.8k | $693.8k |
| Q3 2025 | 0 | — | 3 | $7.8m | $5.1m |
| Q4 2025 | 0 | — | 4 | $38.7m | $7.5m |
| Q1 2026 | 0 | — | 6 | $3.6m | $1.8m |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-03-02 | Savage William Jacob Chief Medical Officer | Sold plan | $486.1k7.4k shares |
| 2026-02-25 | Franchi Jean M. Chief Financial Officer | Sold plan | $24.4k353 shares |
| 2026-02-18 | Franchi Jean M. Chief Financial Officer | Sold plan | $463.6k7.1k shares |
| 2026-02-17 | Quisel John D Chief Executive Officer, director | Sold | $833.8k13.3k shares |
| 2026-02-17 | Stephenson Pamela Chief Commercial Officer | Sold | $347.7k5.5k shares |
| 2026-02-17 | Franchi Jean M. Chief Financial Officer | Sold plan | $256.2k4.1k shares |
| 2026-02-17 | Savage William Jacob Chief Medical Officer | Sold | $204.7k3.3k shares |
| 2026-02-17 | Yu Jonathan Yen-Wen Chief Operating Officer | Sold | $203.1k3.2k shares |
| 2026-02-17 | Khara Rahul Chief Legal Officer | Sold | $179.3k2.9k shares |
| 2026-01-20 | Khara Rahul Chief Legal Officer | Sold plan | $69.7k1.0k shares |
| 2026-01-02 | Khara Rahul Chief Legal Officer | Sold plan | $511.4k6.5k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q1 2026
| Manager | Shares | Change |
|---|---|---|
| FMR LLC 0.02% of their portfolio | 5.6m $357.2m | Added +136.7k |
| RA CAPITAL MANAGEMENT, L.P. 1.66% of their portfolio | 2.5m $156.7m | Added +474.1k |
| BlackRock, Inc. 0.00% of their portfolio | 2.3m $145.4m | Reduced -1.1k |
| WELLINGTON MANAGEMENT GROUP LLP 0.02% of their portfolio | 1.7m $111.0m | Added +217.1k |
| STATE STREET CORP 0.00% of their portfolio | 1.7m $108.6m | Added +510.3k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.01% of their portfolio | 1.5m $99.1m | Reduced -148.7k |
| Atlas Venture Life Science Advisors, LLC 12.25% of their portfolio | 1.5m $96.8m | Unchanged |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 1.4m $87.9m | First filing |
| JPMORGAN CHASE & CO 0.01% of their portfolio | 1.4m $83.4m | Reduced -209.6k |
| Frazier Life Sciences Management, L.P. 2.23% of their portfolio | 1.4m $86.6m | Added +94.9k |
| TCG Crossover Management, LLC 2.45% of their portfolio | 1.3m $85.8m | New |
| BVF INC/IL 2.59% of their portfolio | 1.3m $81.4m | Added +622.3k |
| ORBIMED ADVISORS LLC 1.49% of their portfolio | 1.1m $68.3m | Unchanged |
| Siren, L.L.C. 1.75% of their portfolio | 988.4k $63.2m | Unchanged |
| Woodline Partners LP 0.23% of their portfolio | 958.3k $61.3m | Added +448 |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 744.2k $47.6m | Added +59.3k |
| Vestal Point Capital, LP 1.25% of their portfolio | 700.0k $44.8m | Reduced -35.0k |
| DEERFIELD MANAGEMENT COMPANY, L.P. 0.50% of their portfolio | 657.0k $42.0m | Added +145.8k |
| GOLDMAN SACHS GROUP INC 0.01% of their portfolio | 639.8k $40.9m | Reduced -114.4k |
| JENNISON ASSOCIATES LLC 0.03% of their portfolio | 610.4k $39.0m | Added +78.3k |
| Logos Global Management LP 1.84% of their portfolio | 560.0k $35.8m | Added +50.0k |
| Assenagon Asset Management S.A. 0.06% of their portfolio | 546.2k $34.9m | Added +188.4k |
| ARMISTICE CAPITAL, LLC 1.13% of their portfolio | 536.0k $34.3m | Added +36.6k |
| Bellevue Group AG 0.70% of their portfolio | 459.3k $29.4m | New |
| Saturn V Capital Management LP 5.21% of their portfolio | 449.9k $28.8m | Added +151.5k |
| Opaleye Management Inc. 3.55% of their portfolio | 421.0k $26.9m | Added +221.0k |
| Palo Alto Investors LP 3.93% of their portfolio | 401.7k $25.7m | Added +84.3k |
| EVENTIDE ASSET MANAGEMENT, LLC 0.42% of their portfolio | 395.6k $25.3m | Added +180 |
| DIMENSIONAL FUND ADVISORS LP 0.01% of their portfolio | 394.4k $25.2m | Added +170.9k |
| Pictet Asset Management Holding SA 0.03% of their portfolio | 387.0k $24.7m | Reduced -7.4k |
| Aberdeen Group plc 0.04% of their portfolio | 375.6k $24.0m | Added +141.3k |
| Foresite Capital Management V, LLC 8.83% of their portfolio | 374.1k $23.9m | Added +75.0k |
| BAKER BROS. ADVISORS LP 0.13% of their portfolio | 349.7k $22.4m | Added +12.6k |
| LOOMIS SAYLES & CO L P 0.03% of their portfolio | 317.2k $20.3m | Added +34.8k |
| Checkpoint Capital L.P. 6.58% of their portfolio | 286.7k $18.3m | Reduced -166.3k |
| Octagon Capital Advisors LP 1.91% of their portfolio | 270.0k $17.3m | New |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 251.2k $16.1m | Added +4.2k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 247.3k $15.8m | First filing |
| NORTHERN TRUST CORP 0.00% of their portfolio | 247.2k $15.8m | Added +19.1k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 217.4k $13.9m | First filing |
| Bank of New York Mellon Corp 0.00% of their portfolio | 205.0k $13.1m | Added +137.3k |
| SILVERARC CAPITAL MANAGEMENT, LLC 1.48% of their portfolio | 196.0k $12.5m | New |
| Ensign Peak Advisors, Inc 0.02% of their portfolio | 191.5k $12.2m | Added +14.4k |
| Integral Health Asset Management, LLC 0.58% of their portfolio | 170.0k $10.9m | New |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 166.8k $10.7m | Added +30.8k |
| Bain Capital Life Sciences Investors, LLC 0.81% of their portfolio | 141.2k $9.0m | New |
| BNP PARIBAS FINANCIAL MARKETS 0.01% of their portfolio | 127.7k $8.2m | Added +5.6k |
| Alyeska Investment Group, L.P. 0.02% of their portfolio | 125.0k $8.0m | Added +75.0k |
| Catalio Capital Management, LP 1.64% of their portfolio | 123.0k $7.9m | Added +12.6k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 110.9k $7.1m | Reduced -3.5k |
| KENNEDY CAPITAL MANAGEMENT LLC 0.15% of their portfolio | 108.3k $6.9m | Added +99.0k |
| Atle Fund Management AB 1.03% of their portfolio | 107.3k $3.2m | Added +59.3k |
| UBS Group AG 0.00% of their portfolio | 98.6k $6.3m | Reduced -17.5k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 97.9k $6.3m | Reduced -2.5k |
| DNB Asset Management AS 0.02% of their portfolio | 96.8k $6.2m | Added +12.5k |
| MORGAN STANLEY 0.00% of their portfolio | 94.3k $6.0m | Added +19.4k |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 83.3k $5.3m | Reduced -101.5k |
| Jump Financial, LLC 0.08% of their portfolio | 81.8k $5.2m | New |
| Sofinnova Investments, Inc. 0.25% of their portfolio | 78.3k $5.0m | Reduced -32.7k |
| Freestone Grove Partners LP 0.03% of their portfolio | 68.7k $4.4m | New |
| iA Global Asset Management Inc. 0.06% of their portfolio | 66.2k $4.2m | Reduced -187 |
| Sio Capital Management, LLC 0.60% of their portfolio | 65.2k $4.2m | Added +7.6k |
| Casdin Capital, LLC 0.31% of their portfolio | 65.0k $4.2m | New |
| KVP Capital Advisors, LP 2.78% of their portfolio | 58.2k $3.7m | Unchanged |
| MOORE CAPITAL MANAGEMENT, LP 0.13% of their portfolio | 57.8k $3.7m | New |
| Rafferty Asset Management, LLC 0.01% of their portfolio | 53.9k $3.4m | Added +17.8k |
| SPHERA FUNDS MANAGEMENT LTD. 0.59% of their portfolio | 53.5k $3.4m | New |
| NEXTBio Capital Management LP 1.56% of their portfolio | 52.7k $3.4m | Added +9.9k |
| Nuveen, LLC 0.00% of their portfolio | 51.4k $3.3m | Added +2.9k |
| SCHRODER INVESTMENT MANAGEMENT GROUP 0.00% of their portfolio | 51.0k $3.1m | Added +856 |
| Burkehill Global Management, LP 0.16% of their portfolio | 50.0k $3.2m | Unchanged |
| Swiss National Bank 0.00% of their portfolio | 48.0k $3.1m | Unchanged |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 45.8k $2.9m | Reduced -37.1k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 44.7k $2.7m | Reduced -35.6k |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.00% of their portfolio | 39.9k $2.6m | Reduced -293 |
| LAZARD ASSET MANAGEMENT LLC 0.00% of their portfolio | 39.4k $2.5m | Reduced -18.7k |
| Universal- Beteiligungs- und Servicegesellschaft mbH 0.00% of their portfolio | 38.0k $2.4m | Added +10.7k |
| SEVEN GRAND MANAGERS, LLC 0.15% of their portfolio | 35.0k $2.2m | Unchanged |
| XTX Topco Ltd 0.04% of their portfolio | 34.4k $2.2m | Added +11.3k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 34.4k $2.2m | Added +11.1k |
| BARCLAYS PLC 0.00% of their portfolio | 33.3k $2.1m | Reduced -66.3k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 33.1k $2.1m | Added +3.2k |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 32.5k $2.1m | Reduced -20.0k |
| Brevan Howard Capital Management LP 0.02% of their portfolio | 32.4k $2.0m | Reduced -17.3k |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 31.8k $2.0m | Reduced -31.0k |
| Squarepoint Ops LLC 0.00% of their portfolio | 31.7k $2.0m | Added +16.0k |
| ALPS ADVISORS INC 0.01% of their portfolio | 31.1k $2.0m | Added +56 |
| TUDOR INVESTMENT CORP ET AL 0.01% of their portfolio | 31.0k $2.0m | Reduced -35.1k |
| Invesco Ltd. 0.00% of their portfolio | 30.6k $2.0m | Reduced -30.4k |
| TD Asset Management Inc 0.00% of their portfolio | 30.5k $1.9m | Reduced -39.2k |
| RTW INVESTMENTS, LP 0.02% of their portfolio | 30.0k $1.9m | Unchanged |
| VICTORY CAPITAL MANAGEMENT INC 0.00% of their portfolio | 29.2k $1.9m | Reduced -47.1k |
| BANK OF MONTREAL /CAN/ 0.00% of their portfolio | 28.8k $1.8m | Added +3.9k |
| Nantahala Capital Management, LLC 0.10% of their portfolio | 25.7k $1.6m | Reduced -107.1k |
| PNC Financial Services Group, Inc. 0.00% of their portfolio | 25.3k $1.6m | Added +92 |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 24.5k $1.9m | Unchanged |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 24.4k $1.6m | Added +3.9k |
| PROFUND ADVISORS LLC 0.06% of their portfolio | 24.0k $1.5m | Added +10.5k |
| ALGERT GLOBAL LLC 0.02% of their portfolio | 22.7k $1.5m | New |
| BOOTHBAY FUND MANAGEMENT, LLC 0.03% of their portfolio | 21.4k $1.4m | New |