STOCK TITAN

Mirum (MIRM) director uses options, sells 2,000 pre-planned shares

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

Mirum Pharmaceuticals director Saira Ramasastry exercised options and sold the resulting shares in a planned transaction. On April 15, 2026, she exercised a stock option to acquire 2,000 shares of Mirum common stock at $23.51 per share, from a fully vested option. The same day, she sold 2,000 common shares in an open-market transaction at $96.90 per share, leaving 0 shares of common stock reported as directly owned after the sale. The filing notes the activity occurred under a Rule 10b5-1 trading plan adopted on September 18, 2025, indicating the trades were pre-arranged.

Positive

  • None.

Negative

  • None.
Insider Ramasastry Saira
Role Director
Sold 2,000 shs ($194K)
Type Security Shares Price Value
Exercise Stock Option (right to buy) 2,000 $0.00 --
Exercise Common Stock 2,000 $23.51 $47K
Sale Common Stock 2,000 $96.90 $194K
Holdings After Transaction: Stock Option (right to buy) — 2,000 shares (Direct); Common Stock — 2,000 shares (Direct)
Footnotes (1)
  1. Reported transaction occurred pursuant to a Rule 10b5-1 Plan adopted by the reporting person on September 18, 2025. The stock option is fully vested.
Options exercised 2,000 shares Stock option exercise on April 15, 2026
Exercise price $23.51 per share Strike price of stock option exercised
Shares sold 2,000 shares Open-market sale on April 15, 2026
Sale price $96.90 per share Price for common stock sale
Post-transaction holdings 0 shares Common stock directly owned after sale
10b5-1 plan adoption date September 18, 2025 Date trading plan was adopted
Rule 10b5-1 Plan regulatory
"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.
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.
open-market sale financial
"transaction_action: "open-market sale""
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."
SEC Form 4
FORM 4UNITED 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*
Ramasastry Saira

(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)
XDirector10% Owner
Officer (give title below)Other (specify below)
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
04/15/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm 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)
CodeVAmount(A) or (D)Price
Common Stock04/15/2026M2,000A$23.512,000D
Common Stock04/15/2026S(1)2,000D$96.90D
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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Stock Option (right to buy)$23.5104/15/2026M2,000 (2)06/01/2032Common Stock2,000$02,000D
Explanation of Responses:
1. Reported transaction occurred pursuant to a Rule 10b5-1 Plan adopted by the reporting person on September 18, 2025.
2. The stock option is fully vested.
/s/ Judit Ryvkin, Attorney-in-Fact04/16/2026
** Signature of Reporting PersonDate
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 transaction did Mirum Pharmaceuticals (MIRM) director Saira Ramasastry report?

Director Saira Ramasastry reported exercising stock options for 2,000 Mirum shares and selling all 2,000 shares. The exercise price was $23.51 per share and the shares were sold at $96.90 per share in an open-market transaction.

At what prices did Saira Ramasastry exercise and sell Mirum (MIRM) shares?

She exercised options to acquire 2,000 Mirum shares at $23.51 per share, then sold 2,000 common shares at $96.90 per share. These actions occurred on April 15, 2026, as part of a pre-arranged trading plan.

How many Mirum Pharmaceuticals (MIRM) shares does Saira Ramasastry hold after this Form 4?

After the reported transactions, the Form 4 shows Saira Ramasastry directly owning 0 shares of Mirum common stock. The 2,000 shares acquired through option exercise were sold the same day, and no remaining derivative position is listed.

Was the Mirum (MIRM) insider sale by Saira Ramasastry under a Rule 10b5-1 plan?

Yes. The filing states the reported transaction occurred under a Rule 10b5-1 trading plan adopted by Saira Ramasastry on September 18, 2025. Such plans pre-schedule trades, reducing the significance of short-term market timing.

What type of derivative security did Saira Ramasastry exercise for Mirum (MIRM)?

She exercised a fully vested stock option covering 2,000 Mirum common shares at a $23.51 exercise price. The option, described as a “Stock Option (right to buy),” originally had an expiration date in June 2032 before being fully exercised.

How many Mirum (MIRM) shares did Saira Ramasastry sell in this insider transaction?

She sold 2,000 shares of Mirum common stock in an open-market transaction coded as an “S” sale. The shares were sold at $96.90 per share on April 15, 2026, immediately after exercising options for the same number of shares.