Were the Mirum Pharmaceuticals (MIRM) CEO’s share sales pre-planned under a Rule 10b5-1 plan?

Yes. A footnote states the reported transactions occurred pursuant to a Rule 10b5-1 Plan adopted by Christopher Peetz on March 2, 2026. Rule 10b5-1 plans schedule trades in advance, indicating these sales followed a pre-arranged trading program rather than ad hoc decisions.

How does the Form 4 describe pricing details for the Mirum Pharmaceuticals (MIRM) share sales?

The filing provides weighted average sale prices and price ranges for each transaction group. For example, one group has a weighted average of $121.65 with a range between $121.11 and $122.105. The company offers to supply full price breakdowns upon request.

Mirum CEO sells 20,000 shares after option exercise

Mirum Pharmaceuticals CEO Christopher Peetz exercised stock options for 20,000 shares of common stock at $2.936 per share and sold 20,000 shares in open-market transactions on July 6, 2026 under a Rule 10b5-1 Plan.

Filing Impact

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Form Type

Rhea-AI Filing Summary

Mirum Pharmaceuticals CEO Christopher Peetz exercised stock options for 20,000 shares of common stock at $2.936 per share and sold 20,000 shares in open-market transactions on July 6, 2026 under a Rule 10b5-1 Plan. Following these trades, he holds 196,019 shares directly and 187,500 shares indirectly through The Peetz Family Trust.

Insider Trade Summary 10b5-1

Exercise and Sale: 20,000 shares ($2.39M approx. pre-tax spread)

Exercise and Sale 7 txns

Insider Peetz Christopher

Role CHIEF EXECUTIVE OFFICER

Sold 20,000 shs ($2.45M)

Approx. gross sale proceeds $2.45M

Approx. exercise cost $59K

Approx. pre-tax spread $2.39M

Type	Security	Shares	Price	Value
Exercise	Employee Stock Option (right to buy)	20,000	$0.00	$0.00
Exercise	Common Stock	20,000	$2.936	$59K
Sale	Common Stock	12,134	$121.65	$1.48M
Sale	Common Stock	4,181	$122.34	$512K
Sale	Common Stock	1,975	$123.74	$244K
Sale	Common Stock	1,710	$124.79	$213K
holding	Common Stock	--	--	--

Holdings After Transaction: Employee Stock Option (right to buy) — 108,487 contracts (Direct); Common Stock — 194,309 shares (Direct); Common Stock — 187,500 shares (Indirect, By The Peetz Family Trust)

Footnotes (6)

F1. Reported transaction occurred pursuant to a Rule 10b5-1 Plan adopted by the reporting person on March 2, 2026.
F2. The weighted average sale price for the transaction reported was $121.65, and the range of prices were between $121.11 and $122.105. 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.
F3. The weighted average sale price for the transaction reported was $122.34, and the range of prices were between $122.13 and $123.1125. 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.
F4. The weighted average sale price for the transaction reported was $123.74, and the range of prices were between $123.24 and $124.10. 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.
F5. The weighted average sale price for the transaction reported was $124.79, and the range of prices were between $124.27 and $124.94. 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.
F6. The stock option is fully vested.

Key Figures

Shares sold: 20,000 shares Sale prices: $121.11–$124.94/share Options exercised: 20,000 shares +5 more

8 metrics

Shares sold 20,000 shares Open-market sales on July 6, 2026

Sale prices $121.11–$124.94/share Reported price ranges with weighted averages

Options exercised 20,000 shares Employee Stock Option exercise on July 6, 2026

Exercise price $2.936/share Conversion or exercise price for 20,000 options

Direct holdings after 196,019 shares Common stock held directly after transactions

Indirect holdings 187,500 shares Held by The Peetz Family Trust

Rule 10b5-1 plan date March 2, 2026 Adoption date for pre-planned trading program

Option expiration March 11, 2029 Original expiration date of exercised option grant

Key Terms

Rule 10b5-1 Plan, Employee Stock Option (right to buy), weighted average sale price, open-market sale, +1 more

5 terms

Rule 10b5-1 Plan regulatory

"Reported transaction occurred pursuant to a Rule 10b5-1 Plan adopted by the reporting person on March 2, 2026."

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.

Employee Stock Option (right to buy) financial

"security_title: "Employee Stock Option (right to buy)" with 20,000.0000 shares exercised."

weighted average sale price financial

"The weighted average sale price for the transaction reported was $121.65, and the range of prices were between $121.11 and $122.105."

open-market sale financial

"transaction_action: "open-market sale" with transaction_code "S" for common stock."

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

fully vested financial

"The stock option is fully vested."

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transactions did Mirum Pharmaceuticals (MIRM) CEO report on July 6, 2026?

Mirum Pharmaceuticals CEO Christopher Peetz exercised options for 20,000 shares at $2.936 and sold 20,000 common shares in open-market transactions on July 6, 2026. These trades were reported in a Form 4 insider filing with updated post-transaction holdings.

How many Mirum Pharmaceuticals (MIRM) shares did the CEO sell and at what prices?

Christopher Peetz sold 20,000 Mirum Pharmaceuticals common shares in several trades at prices from about $121.11 to $124.94. Reported individual transactions include 1,710 shares at $124.79, 1,975 at $123.74, 4,181 at $122.34, and 12,134 at a weighted $121.65.

What stock options did the Mirum Pharmaceuticals (MIRM) CEO exercise in this Form 4?

The CEO exercised an Employee Stock Option for 20,000 Mirum Pharmaceuticals shares at a conversion or exercise price of $2.936 per share. The option is fully vested and was originally scheduled to expire on March 11, 2029, according to the filing details and footnotes.

What are Christopher Peetz’s Mirum Pharmaceuticals (MIRM) shareholdings after these transactions?

After the July 6, 2026 transactions, Christopher Peetz holds 196,019 Mirum Pharmaceuticals common shares directly. In addition, a separate holding entry reports 187,500 shares held indirectly through The Peetz Family Trust, reflecting his total visible equity exposure in the company from this filing.

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

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Accepted by SEC EDGAR 07/08/2026 - 05:12 PM EDT

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).

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

CALIFORNIA

94404

(City)

(State)

(Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
07/06/2026

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	07/06/2026		M		20,000	A	$2.936	214,309	D
Common Stock	07/06/2026		S⁽¹⁾		12,134	D	$121.65⁽²⁾	202,175	D
Common Stock	07/06/2026		S⁽¹⁾		4,181	D	$122.34⁽³⁾	197,994	D
Common Stock	07/06/2026		S⁽¹⁾		1,975	D	$123.74⁽⁴⁾	196,019	D
Common Stock	07/06/2026		S⁽¹⁾		1,710	D	$124.79⁽⁵⁾	194,309	D
Common Stock								187,500	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Employee Stock Option (right to buy)	$2.936	07/06/2026		M			20,000	⁽⁶⁾	03/11/2029	Common Stock	20,000	$0	108,487	D

Explanation of Responses:

1. Reported transaction occurred pursuant to a Rule 10b5-1 Plan adopted by the reporting person on March 2, 2026.

2. The weighted average sale price for the transaction reported was $121.65, and the range of prices were between $121.11 and $122.105. 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 weighted average sale price for the transaction reported was $122.34, and the range of prices were between $122.13 and $123.1125. 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.

4. The weighted average sale price for the transaction reported was $123.74, and the range of prices were between $123.24 and $124.10. 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.

5. The weighted average sale price for the transaction reported was $124.79, and the range of prices were between $124.27 and $124.94. 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.

6. The stock option is fully vested.

	/s/ Judit Ryvkin, Attorney-in-Fact	07/08/2026
	** 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)

Source: View Original Filing on SEC EDGAR