Mirum Director Sells $400K Amid 91% Stock Surge -- Here's What the Firm Expects for 2026
Key Points
A director at Mirum Pharmaceuticals sold 5,000 shares of the company for $400,000 on Dec. 22.
The entire transaction was direct, involving the exercise of vested stock options, immediately sold as shares.
No indirect entities or trusts were involved.
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Saira Ramasastry, a director at Mirum Pharmaceuticals (NASDAQ:MIRM), executed the exercise of 5,000 stock options followed by an immediate open-market sale of the resulting shares for a total transaction value of $400,000 on Dec. 22, according to a recent SEC Form 4 filing.
Transaction summary
| Metric | Value |
|---|---|
| Shares sold (direct) | 5,000 |
| Transaction value | $400,000 |
| Post-transaction common shares (direct) | 0 |
Transaction value based on SEC Form 4 weighted average purchase price ($80.00); post-transaction value is $0 as no common shares remained after the transaction.
Key questions
- What type of transaction occurred and how was it structured?
The transaction involved the exercise of 5,000 vested stock options by Saira Ramasastry, immediately followed by the sale of all resulting shares in the open market, with no participation from indirect entities or trusts. - How material was this event relative to Ramasastry's overall ownership?
The sale accounted for 100% of her direct common stock holdings. - What is the residual equity exposure post-transaction?
After this transaction, Ramasastry holds no direct or indirect shares of common stock, as reported by the Form 4 filing.
Company overview
| Metric | Value |
|---|---|
| Revenue (TTM) | $471.79 million |
| Net income (TTM) | ($41.42 million) |
| 1-year price change | 90.71% |
* 1-year performance calculated using Dec. 22 as the reference date.
Company snapshot
- Mirum develops and commercializes therapies for rare and orphan liver diseases, with LIVMARLI as its lead product, and additional candidates such as Volixibat in its pipeline.
- The company targets patients with rare liver disorders, including progressive familial intrahepatic cholestasis, Alagille syndrome, and biliary atresia.
Mirum is a biopharmaceutical company specializing in the development of innovative therapies for debilitating rare liver diseases.
What this transaction means for investors
Ramasastry’s transaction was executed under a Rule 10b5-1 plan and involved exercising 5,000 options before immediately selling the resulting shares. Notably, she still holds 10,000 options, preserving upside exposure even after eliminating direct common stock holdings. With shares up roughly 91% over the past year and far outpacing the broader market, an option exercise and sale under a pre-set plan like this one looks more like compensation mechanics than a shift in conviction.
Meanwhile, Mirum Pharmaceuticals continues to execute operationally. Preliminary 2025 results released on Monday show net product sales of about $520 million, beating the high end of guidance, and management now forecasts $630 million to $650 million in global net product sales for 2026. The company also ended 2025 with an estimated $392 million in cash and investments and achieved positive operating cash flow, giving it flexibility to fund pipeline expansion and the proposed Bluejay Therapeutics acquisition, which is expected to close this month. "2025 was an excellent year for Mirum, reflecting the strength and scalability of our purpose-built rare disease operating model," CEO Chris Peetz said in the Monday release.
Glossary
Stock options: Contracts granting the right to buy company shares at a set price within a specific period.
Exercise (of options): The act of using stock options to purchase shares at the predetermined price.
Vested: Refers to stock options or benefits that are fully earned and available to the holder.
Open-market sale: Selling shares directly on a public stock exchange, rather than through private transactions.
Disposition: The act of selling or otherwise transferring ownership of an asset.
Direct holdings: Shares owned personally, not through trusts or other entities.
Indirect entities: Organizations or structures, like trusts, that can hold shares on behalf of an individual.
Equity position: Ownership interest in a company, typically through holding its shares.
Common stock: A class of shares representing ownership in a company and a claim on part of its profits.
Trading plan: A prearranged program for buying or selling securities, often to comply with insider trading regulations.
Orphan diseases: Rare medical conditions affecting a small percentage of the population, often lacking effective treatments.
TTM: The 12-month period ending with the most recent quarterly report.
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Jonathan Ponciano has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Mirum Pharmaceuticals. The Motley Fool has a disclosure policy.
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