Kevin Bitterman - 01 Sep 2026 Form 4 Insider Report for Disc Medicine, Inc. (IRON)

Reporting relationship: Director
Issuer ticker: IRON
Reported as of: 01 Sep 2026
Net transaction value: -$4,367,944
SEC form: 4
Accepted by SEC: 03 Sep 2026, 17:43:43 UTC
Prior SEC filing: 23 Jun 2026
Source filing: View source filing
Reporting owner signature: /s/ Ommer Chohan, Attorney-in-Fact

Key filing fact

Kevin Bitterman filed Form 4 for Disc Medicine, Inc. (IRON) on 03 Sep 2026.

Key facts

This page summarizes Kevin Bitterman's Form 4 filing for Disc Medicine, Inc. (IRON).
12 reported transactions and 0 derivative rows are listed below.
Accepted by SEC: 03 Sep 2026, 17:43.

Change

Previous filing in this sequence was filed on 23 Jun 2026.
Current net transaction value: -$4,367,944.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001591747 Primary reporting owner

Bitterman Kevin

Relationship: Director
Address: C/O DISC MEDICINE, INC., 321 ARSENAL STREET, SUITE 101, WATERTOWN
Signature: /s/ Ommer Chohan, Attorney-in-Fact
Signature date: 03 Sep 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

IRON transaction

Common Stock

Sale

Transaction value: $5,596
Shares: -70
Change %: -0.02%
Price: $79.95
Shares after: 349,140
Date: 01 Sep 2026
Ownership: See footnote
Footnotes: F1, F2

IRON transaction

Common Stock

Sale

Transaction value: $4,637
Shares: -58
Change %: -0.02%
Price: $79.95
Shares after: 337,427
Date: 01 Sep 2026
Ownership: See footnote
Footnotes: F1, F3

IRON transaction

Common Stock

Sale

Transaction value: $79.95
Shares: -1
Change %: -0.01%
Price: $79.95
Shares after: 14,012
Date: 01 Sep 2026
Ownership: See footnote
Footnotes: F1, F4

IRON transaction

Common Stock

Sale

Transaction value: $2,127,872
Shares: -26,542
Change %: -7.6%
Price: $80.17
Shares after: 322,598
Date: 02 Sep 2026
Ownership: See footnote
Footnotes: F1, F2, F5

IRON transaction

Common Stock

Sale

Transaction value: $1,770,955
Shares: -22,090
Change %: -6.5%
Price: $80.17
Shares after: 315,337
Date: 02 Sep 2026
Ownership: See footnote
Footnotes: F1, F3, F5

IRON transaction

Common Stock

Sale

Transaction value: $40,967
Shares: -511
Change %: -3.6%
Price: $80.17
Shares after: 13,501
Date: 02 Sep 2026
Ownership: See footnote
Footnotes: F1, F4, F5

IRON transaction

Common Stock

Sale

Transaction value: $810
Shares: -10
Change %: -0%
Price: $80.98
Shares after: 322,588
Date: 02 Sep 2026
Ownership: See footnote
Footnotes: F1, F2, F6

IRON transaction

Common Stock

Sale

Transaction value: $729
Shares: -9
Change %: -0%
Price: $80.98
Shares after: 315,328
Date: 02 Sep 2026
Ownership: See footnote
Footnotes: F1, F3, F6

IRON transaction

Common Stock

Sale

Transaction value: $162
Shares: -2
Change %: -0.01%
Price: $80.98
Shares after: 13,499
Date: 02 Sep 2026
Ownership: See footnote
Footnotes: F1, F4, F6

IRON transaction

Common Stock

Sale

Transaction value: $224,744
Shares: -2,810
Change %: -0.87%
Price: $79.98
Shares after: 319,778
Date: 03 Sep 2026
Ownership: See footnote
Footnotes: F1, F2, F7

IRON transaction

Common Stock

Sale

Transaction value: $187,073
Shares: -2,339
Change %: -0.74%
Price: $79.98
Shares after: 312,989
Date: 03 Sep 2026
Ownership: See footnote
Footnotes: F1, F3, F7

IRON transaction

Common Stock

Sale

Transaction value: $4,319
Shares: -54
Change %: -0.4%
Price: $79.98
Shares after: 13,445
Date: 03 Sep 2026
Ownership: See footnote
Footnotes: F1, F4, F7

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 7 footnotes

Footnote F1

Shares were sold pursuant to a Rule 10b5-1 trading plan adopted on July 30, 2026.

Footnote F2

These shares are held by Atlas Venture Opportunity Fund I, L.P. ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, L.P. ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

Footnote F3

These shares are held by Atlas Venture Opportunity Fund II, L.P. ("Opportunity II"). The general partner of Opportunity II is Atlas Venture Associates Opportunity II, L.P. ("Associates II"). Atlas Venture Associates Opportunity II, LLC ("Associates II LLC") is the general partner of Associates II. The Reporting Person is a member of Associates II LLC and disclaims beneficial ownership of such securities held by Opportunity II, except to the extent of his pecuniary interest therein, if any.

Footnote F4

These shares are held by Atlas Venture Fund XII, L.P. ("Atlas XII"). The general partner of Atlas XII is Atlas Venture Associates XII, L.P. ("Associates XII"). Atlas Venture Associates XII, LLC ("Associates XII LLC") is the general partner of Associates XII. The Reporting Person is a member of Associates XII LLC and disclaims beneficial ownership of such securities held by Atlas XII, except to the extent of his pecuniary interest therein, if any.

Footnote F5

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $79.95 to $80.9421 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Footnote F6

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $80.9677 to $81.0079 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Footnote F7

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $79.95 to $80.28 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.