Mirum Pharmaceuticals, Inc. (MIRM) CEO trades 40,000 shares via options

Rhea-AI Filing Summary

Mirum Pharmaceuticals CEO Christopher Peetz exercised employee stock options for 40,000 shares of common stock at $2.936 per share on August 7, 2025, then sold 40,000 shares at a weighted average sale price of $55.251022 (range $55.25–$55.485). After these transactions he holds 138,641 shares of common stock directly and 208,570 shares indirectly through The Peetz Family Trust; the stock option is fully vested and expires March 11, 2029.

Insights

Securities Analyst

TL;DR: Routine insider option exercise and planned sale under a 10b5-1 plan; factual disclosure without new corporate guidance.

The filing documents a simultaneous exercise of 40,000 options at a strike of $2.936 and the sale of 40,000 shares at a weighted average of $55.251 executed under a 10b5-1 plan adopted on 11/22/2024. The option is noted as fully vested, and the report specifies both direct and indirect beneficial ownership amounts. From a market-impact perspective, this is a clear, prearranged insider disposition and an option exercise rather than an ad-hoc sale or change in corporate outlook.

Corporate Governance Expert

TL;DR: Disclosure appears complete for Section 16 purposes; transactions tied to a documented 10b5-1 plan and vested options.

The report identifies the reporting person as both CEO and a director and states the transaction was executed pursuant to a Rule 10b5-1 trading plan. The filing includes the weighted average sale price, price range, and notes the option is fully vested—key items for transparency. The presence of indirect holdings via The Peetz Family Trust is explicitly disclosed. No material non-disclosure or governance irregularity is evident from the filed information alone.

Insider Trade Summary

Exercise and Sale: 40,000 shares ($2.09M approx. pre-tax spread)

Exercise and Sale 4 txns

Insider Peetz Christopher

Role CHIEF EXECUTIVE OFFICER

Sold 40,000 shs ($2.21M)

Approx. gross sale proceeds $2.21M

Approx. exercise cost $117K

Approx. pre-tax spread $2.09M

Type	Security	Shares	Price	Value
Exercise	Employee Stock Option (right to buy)	40,000	$0.00	$0.00
Exercise	Common Stock	40,000	$2.936	$117K
Sale	Common Stock	40,000	$55.251	$2.21M
holding	Common Stock	--	--	--

Holdings After Transaction: Employee Stock Option (right to buy) — 198,487 shares (Direct); Common Stock — 138,641 shares (Direct); Common Stock — 208,570 shares (Indirect, By The Peetz Family Trust)

Footnotes (3)

1. F1. Reported transaction occurred pursuant to a Rule 10b5-1 Plan adopted by the reporting person on November 22, 2024.
2. F2. The weighted average sale price for the transaction reported was $55.251022, and the range of prices were between $55.25 and $55.485. Upon request by the SEC staff, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price will be provided.
3. F3. The stock option is fully vested.

Key Figures

Options Exercised: 40,000 shares Option Strike Price: $2.936 per share Shares Sold: 40,000 shares +4 more

7 metrics

Options Exercised 40,000 shares Employee stock options exercised into common stock on August 7, 2025

Option Strike Price $2.936 per share Conversion or exercise price for the employee stock option

Shares Sold 40,000 shares Common stock sale reported with transaction code S on August 7, 2025

Weighted Average Sale Price $55.251022 per share Sale price for the reported transaction, with trades between $55.25 and $55.485

Direct Common Stock Holdings 138,641 shares Post-transaction Mirum common stock held directly by Christopher Peetz

Indirect Trust Holdings 208,570 shares Common stock held indirectly through The Peetz Family Trust after the transaction

Option Expiration Date 2029-03-11 Expiration date of the exercised employee stock option

Key Terms

Rule 10b5-1 Plan, weighted average sale price, Employee Stock Option, indirect ownership

4 terms

Rule 10b5-1 Plan financial

"Reported transaction occurred pursuant to a Rule 10b5-1 Plan adopted by the reporting person"

A Rule 10b5-1 plan is a prearranged, written schedule that lets corporate insiders buy or sell company stock at set times or amounts, even if they later learn material nonpublic information. Think of it like setting an automatic thermostat for trades: it creates a clear record that trades were planned in advance, reducing the risk of insider-trading accusations and helping investors trust that insider transactions are routine rather than based on secret information.

weighted average sale price financial

"The weighted average sale price for the transaction reported was $55.251022"

Employee Stock Option financial

"security_title: Employee Stock Option (right to buy)"

An employee stock option is a promise that lets a worker buy company shares later at a predetermined price, often after they stay for a certain period or meet performance goals — think of it like a coupon that locks in today's price for a future purchase. It matters to investors because options align employees’ incentives with company performance, can increase the number of shares outstanding (dilution) when exercised, and represent a compensation cost that affects reported profits and shareholder value.

indirect ownership financial

"Common Stock held indirectly By The Peetz Family Trust"

AI-generated analysis. How Rhea-AI works. Not financial advice.

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Form 4 Insider Transactions: What Each Field Means →

Accepted by SEC EDGAR 08/08/2025 - 04:49 PM Learn about SEC filing dates

FAQ

What options did MIRM CEO Christopher Peetz exercise in this Form 4?

Christopher Peetz exercised 40,000 employee stock options into common stock at a strike price of $2.936 per share. The filing notes the stock option is fully vested and carries an expiration date of March 11, 2029.

How many Mirum Pharmaceuticals (MIRM) shares did Christopher Peetz sell?

On August 7, 2025, Christopher Peetz sold 40,000 shares of Mirum common stock. The filing reports a weighted average sale price of $55.251022 per share, with individual trades executed between $55.25 and $55.485.

What are Christopher Peetz’s holdings in Mirum Pharmaceuticals (MIRM) after the transactions?

Following the reported transactions, Christopher Peetz holds 138,641 Mirum common shares directly. He also has indirect ownership of 208,570 shares held through The Peetz Family Trust, as disclosed in the Form 4 holding entry.

Was the MIRM insider transaction under a Rule 10b5-1 plan?

The filing states that a reported transaction occurred pursuant to a Rule 10b5-1 Plan adopted by Christopher Peetz on November 22, 2024. This indicates at least one trade was executed under a pre-arranged trading plan framework.

When does the exercised Mirum Pharmaceuticals (MIRM) stock option expire?

The employee stock option exercised by Christopher Peetz in the Form 4 carries an expiration date of March 11, 2029. This date marks the end of the period during which the option could have been exercised into Mirum common stock.

What was the price range for Christopher Peetz’s sale of MIRM shares?

The filing reports a weighted average sale price of $55.251022 per share for the transaction. The individual sale prices for Mirum shares traded during that transaction ranged between $55.25 and $55.485, according to the disclosed footnote.

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^*

Peetz Christopher

(Last) (First) (Middle)

C/O MIRUM PHARMACEUTICALS, INC.

989 E HILLSDALE BLVD., SUITE 300

(Street)

FOSTER CITY CA 94404

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Mirum Pharmaceuticals, Inc. [ MIRM ]

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

3. Date of Earliest Transaction (Month/Day/Year)
08/07/2025

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

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

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

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	08/07/2025		M		40,000	A	$2.936	178,641	D
Common Stock	08/07/2025		S(1)		40,000	D	$55.251(2)	138,641	D
Common Stock								208,570	I	By The Peetz Family Trust

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
Employee Stock Option (right to buy)	$2.936	08/07/2025		M			40,000	(3)	03/11/2029	Common Stock	40,000	$0	198,487	D

Explanation of Responses:

1. Reported transaction occurred pursuant to a Rule 10b5-1 Plan adopted by the reporting person on November 22, 2024.

2. The weighted average sale price for the transaction reported was $55.251022, and the range of prices were between $55.25 and $55.485. Upon request by the SEC staff, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price will be provided.

3. The stock option is fully vested.

	/s/ Judit Ryvkin, Attorney-in-Fact	08/08/2025
	** 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.