Disc Medicine (NASDAQ: IRON) CEO trades 34K shares under Rule 10b5-1 plan

Rhea-AI Filing Summary

Disc Medicine, Inc.’s CEO John D. Quisel reported mixed insider activity in Common Stock. On June 18, 2026, he sold a total of 34,000 shares in open-market transactions at weighted average prices within ranges from $69.35 to $71.85 per share under a pre-arranged Rule 10b5-1 trading plan. On the same date, he exercised a stock option to acquire 34,000 shares of Common Stock at an exercise price of $9.86 per share. After these transactions, he directly holds 226,064 shares of Common Stock and 41,375 stock options remain outstanding, indicating a sizable continuing equity stake.

Insights

Insider trading and governance analyst

CEO executed a planned exercise-and-sell, retaining a substantial equity stake.

The CEO, John D. Quisel, both exercised stock options and sold shares in Disc Medicine, Inc.. He exercised 34,000 options at an exercise price of $9.86 per share, converting a derivative position into common stock, and sold an equal number of shares in open-market trades.

Footnotes state these sales were made under a Rule 10b5-1 trading plan adopted on March 12, 2026. Such pre-arranged plans typically indicate routine portfolio management rather than opportunistic timing. Reported sale prices used weighted averages within ranges from $69.35 to $71.85 per share.

Following the transactions, Quisel directly owns 226,064 common shares and holds 41,375 remaining stock options expiring in 2031. The filing shows a notable but not transformative net sale relative to his remaining position. Overall impact on the broader investment thesis appears limited.

Insider Trade Summary 10b5-1

Net Seller: 34,000 shares ($2,387,296)

Net Sell 5 txns

Insider Quisel John D

Role Chief Executive Officer

Sold 34,000 shs ($2.39M)

Type	Security	Shares	Price	Value
Exercise	Stock Option (Right to Buy)	34,000	$0.00	--
Exercise	Common Stock	34,000	$9.86	$335K
Sale	Common Stock	22,927	$69.9184	$1.60M
Sale	Common Stock	9,522	$70.70	$673K
Sale	Common Stock	1,551	$71.6126	$111K

Holdings After Transaction: Stock Option (Right to Buy) — 41,375 shares (Direct, null); Common Stock — 260,064 shares (Direct, null)

Footnotes (1)

1. These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted on March 12, 2026. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $69.35 to $70.33, 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 ranges set forth in footnotes (2), (3) and (4) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $70.36 to $71.35, inclusive. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $71.36 to $71.85, inclusive. The shares underlying this option are fully vested and exercisable as of the date hereof.

Key Figures

Shares sold: 34,000 shares Sale price ranges: $69.35–$71.85 per share Options exercised: 34,000 shares +5 more

8 metrics

Shares sold 34,000 shares Common Stock open-market sales on June 18, 2026

Sale price ranges $69.35–$71.85 per share Weighted-average sale prices across multiple transactions

Options exercised 34,000 shares Stock Option (Right to Buy) exercised on June 18, 2026

Option exercise price $9.86 per share Exercise price for 34,000 stock options

Shares held after 226,064 shares CEO’s direct Common Stock holdings following transactions

Remaining options 41,375 options Stock options outstanding after exercise, expiring 2031-09-13

Net buy/sell shares 34,000 shares net sold Transaction summary net Buy/Sell direction 'net-sell'

Rule 10b5-1 plan adoption date March 12, 2026 Date CEO adopted the trading plan used for these sales

Key Terms

Rule 10b5-1 trading plan, weighted average price, Stock Option (Right to Buy), derivative security, +1 more

5 terms

Rule 10b5-1 trading plan regulatory

"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted on March 12, 2026."

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

weighted average price financial

"The price reported in Column 4 is a weighted average price."

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

Stock Option (Right to Buy) financial

"security_title: "Stock Option (Right to Buy)""

derivative security financial

"transaction_code_description: "Exercise or conversion of derivative security""

A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.

Common Stock financial

"security_title: "Common Stock""

Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.

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Form 4 Insider Transactions: What Each Field Means →

Available on EDGAR 06/23/2026 - 05:16 PM Accepted by SEC EDGAR 06/23/2026 - 05:16 PM Learn about SEC filing dates

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Quisel John D

(Last) (First) (Middle)

C/O DISC MEDICINE, INC.

321 ARSENAL STREET, SUITE 101

(Street)

WATERTOWN MASSACHUSETTS 02472

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Disc Medicine, Inc. [ IRON ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Executive Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
06/18/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	06/18/2026		M(1)		34,000	A	$9.86	260,064	D
Common Stock	06/18/2026		S(1)		22,927	D	$69.9184(2)	237,137	D
Common Stock	06/18/2026		S(1)		9,522	D	$70.7(3)	227,615	D
Common Stock	06/18/2026		S(1)		1,551	D	$71.6126(4)	226,064	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	$9.86	06/18/2026		M(1)			34,000	(5)	09/13/2031	Common Stock	34,000	$0	41,375	D

Explanation of Responses:

1. These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted on March 12, 2026.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $69.35 to $70.33, 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 ranges set forth in footnotes (2), (3) and (4) to this Form 4.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $70.36 to $71.35, inclusive.

4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $71.36 to $71.85, inclusive.

5. The shares underlying this option are fully vested and exercisable as of the date hereof.

	By: /s/ Rahul Khara, as Attorney-in-Fact	06/23/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transactions did IRON CEO John D. Quisel report on June 18, 2026?

CEO John D. Quisel reported both an option exercise and share sales. He exercised 34,000 stock options at $9.86 per share and sold 34,000 Common Stock shares in open-market trades at weighted average prices within the $69.35–$71.85 range.

How many Disc Medicine (IRON) shares did the CEO sell and at what prices?

John D. Quisel sold a total of 34,000 Common Stock shares. The filing reports weighted average sale prices, with trades executed in multiple transactions at prices ranging from $69.35 up to $71.85 per share across the disclosed ranges.

Were the IRON insider stock sales made under a Rule 10b5-1 trading plan?

Yes. The footnotes state the transactions were effected under a Rule 10b5-1 trading plan adopted on March 12, 2026. Such pre-arranged plans schedule trades in advance and are commonly used to separate routine selling from discretionary timing decisions.

What option exercise did the Disc Medicine (IRON) CEO report in this Form 4?

The CEO exercised a stock option covering 34,000 Common Stock shares. The option, described as a Stock Option (Right to Buy), had an exercise price of $9.86 per share and the underlying shares were fully vested and exercisable as of the transaction date.

How many Disc Medicine (IRON) shares does the CEO hold after these transactions?

After the reported transactions, John D. Quisel directly holds 226,064 shares of Disc Medicine Common Stock. In addition, the filing shows 41,375 stock options remaining outstanding, providing further potential equity exposure if exercised before their stated 2031 expiration.

What is the net effect of the IRON CEO’s June 18, 2026 transactions on his share count?

The transaction summary shows 34,000 shares sold and 34,000 shares acquired via option exercise, resulting in a net sale of 34,000 shares. Despite this net disposition, the CEO continues to hold over two hundred thousand shares plus outstanding stock options.