Mirum Pharmaceuticals (MIRM) director converts 3,977 RSUs into 9,680-share holding

Rhea-AI Filing Summary

Mirum Pharmaceuticals director Lon Cardon exercised 3,977 restricted stock units into common stock. These units each converted into one share on May 29, 2026, increasing his directly held common stock to 9,680 shares. The filing shows an equity award vesting, with no open‑market buying or selling.

Insights

Equity compensation analyst

Routine RSU vesting converts into common shares without market trades.

Director Lon Cardon exercised 3,977 restricted stock units, each representing a right to receive one Mirum common share. This is a standard equity compensation event, not an open-market purchase or sale, and reflects previously granted awards vesting.

After the conversion, he holds 9,680 shares of common stock directly. No remaining derivative holdings are listed in this filing, indicating these RSUs were fully settled. The filing does not change cash balances, as the exercise price is reported as $0.00 per unit.

Insider Trade Summary

3,977 shares exercised/converted

Mixed 2 txns

Insider Cardon Lon

Role null

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Units	3,977	$0.00	--
Exercise	Common Stock	3,977	$0.00	--

Holdings After Transaction: Restricted Stock Units — 0 shares (Direct, null); Common Stock — 9,680 shares (Direct, null)

Footnotes (1)

1. Each restricted stock unit represents a contingent right to receive one share of common stock (or its cash equivalent, at the discretion of the Issuer). Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock and vests on May 29, 2026.

Key Figures

RSUs exercised: 3,977 units Common shares received: 3,977 shares Shares held after: 9,680 shares +2 more

5 metrics

RSUs exercised 3,977 units Restricted Stock Units converted to common stock on May 29, 2026

Common shares received 3,977 shares Shares of Mirum common stock from RSU conversion

Shares held after 9,680 shares Total Mirum common stock directly owned after transaction

Exercise price $0.00 per unit Reported transaction price per RSU in the Form 4

Transaction code M Exercise or conversion of derivative security

Key Terms

Restricted Stock Units, derivative security, contingent right

3 terms

Restricted Stock Units financial

"The security titled "Restricted Stock Units" converted into Mirum common stock."

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

derivative security financial

"The transaction code description notes an "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.

contingent right financial

"Each restricted stock unit represents a contingent right to receive one share of common stock."

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Form 4 Insider Transactions: What Each Field Means →

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^*

Cardon Lon

(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
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/29/2026

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	05/29/2026		M		3,977	A	(1)	9,680	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
Restricted Stock Units	(1)	05/29/2026		M			3,977	(2)	(2)	Common Stock	3,977	$0	0	D

Explanation of Responses:

1. Each restricted stock unit represents a contingent right to receive one share of common stock (or its cash equivalent, at the discretion of the Issuer).

2. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock and vests on May 29, 2026.

	/s/ Judit Ryvkin, Attorney-in-Fact	06/02/2026
	** 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 did Mirum Pharmaceuticals (MIRM) director Lon Cardon report in this Form 4?

Lon Cardon reported exercising 3,977 restricted stock units into Mirum Pharmaceuticals common stock. Each unit converted into one share, increasing his direct holdings to 9,680 shares. This reflects vesting of prior equity awards rather than an open-market stock purchase or sale.

How many Mirum Pharmaceuticals (MIRM) shares does Lon Cardon hold after this transaction?

Following the transaction, Lon Cardon directly holds 9,680 shares of Mirum Pharmaceuticals common stock. This total reflects the addition of 3,977 shares received from exercising restricted stock units, as disclosed in the Form 4 insider trading report filed for the May 29, 2026 transaction.

Was there any open-market buying or selling in Lon Cardon’s Mirum (MIRM) Form 4 filing?

No, the Form 4 does not show any open-market buying or selling. It reports an exercise of 3,977 restricted stock units into common stock, a compensation-related conversion event. The transaction code “M” indicates derivative exercise or conversion, not a market trade for cash.

What do the restricted stock units in the Mirum (MIRM) filing represent?

Each restricted stock unit represents a contingent right to receive one share of Mirum common stock, or its cash equivalent at the issuer’s discretion. In this filing, 3,977 units vested and converted into 3,977 common shares on May 29, 2026, settling the entire RSU position reported.

How many restricted stock units did Lon Cardon have after this Mirum (MIRM) transaction?

After the transaction, the reported restricted stock unit position is zero. The Form 4 shows 3,977 RSUs exercised and converted into an equal number of Mirum common shares, leaving no remaining RSUs in this specific award according to the post-transaction derivative holdings column.