Floyd Petersen, director of Amphastar Pharmaceuticals (AMPH 3.18%), exercised 16,679 options for common stock and immediately sold all resulting shares in a transaction valued at $441,836.72, as disclosed in a SEC Form 4 filing.
Transaction summary
| Metric | Value |
|---|---|
| Shares sold | 16,679 |
| Transaction value | ~$441,800 |
| Post-transaction shares | 75,531 |
| Post-transaction value (direct ownership) | ~$2 million |
Transaction value based on SEC Form 4 weighted average purchase price ($26.49); post-transaction value based on Nov. 13, 2025 market close ($26.37).

NASDAQ: AMPH
Key Data Points
Key questions
- How does the size of this transaction compare to Petersen's historical selling activity?
The sale of 16,679 shares on November 13, 2025, is materially larger than the historical median sell-only transaction of 500 shares. - What is the derivative context of this transaction?
All 16,679 shares sold originated from the exercise of fully vested stock options, with immediate disposition in the open market. - How does the transaction value relate to Petersen Floyd F.'s remaining direct ownership?
Following the sale, Petersen Floyd F. retains 75,531 shares with an approximate market value of $2.0 million as of November 13, 2025, reflecting a 4% reduction in direct holdings since May 2024. - What was the market context at the time of the sale?
Shares were priced at around $26.49 per share for the transaction, with the stock closing at $26.37 on November 13, 2025. Over the prior 12 months, the stock declined by 42% as of the transaction date.
Company overview
| Metric | Value |
|---|---|
| Price (as of market close 11/13/25) | $26.49 |
| Market capitalization | $1.20 billion |
| Revenue (TTM) | $723.31 million |
| Net income (TTM) | $111.63 million |
* 1-year performance is calculated using November 13th, 2025 as the reference date.
Company snapshot
- Offers a diversified portfolio of injectable, inhalation, and intranasal pharmaceutical products, including Primatene Mist, Enoxaparin, Naloxone, Glucagon, and specialty APIs.
- Generates revenue through the development, manufacturing, and sale of both generic and proprietary drugs, with a focus on specialty and emergency-use medications.
- Serves hospitals, care facilities, alternate care sites, clinics, and physicians, primarily targeting the U.S. China, and France markets.
Amphastar Pharmaceuticals, Inc. is a mid-cap biopharmaceutical company specializing in specialty and generic injectable and inhalation products. The company leverages a vertically integrated model, with in-house API production and a diverse product pipeline, to address critical needs in acute care and emergency medicine. Its strategic focus on both proprietary and generic products positions it to capture demand from institutional healthcare providers and respond to evolving market opportunities.
Foolish take
Floyd Petersen's share sale on Nov. 13 was an exercise and sell move in which the executive exercised his right to purchase 16,679 shares at $16.69 a piece and sold the shares immediately on the open market for $26.49 a piece, a total sale value of $441,800.
Amphastar Pharmaceuticals stock was down 42% on the year on the day of the transaction, compared to a 14% total return for the S&P 500. The stock is up 5% over the last month as of Dec. 23, after the company announced the FDA had approved its abbreviated New Drug Application for a teriparatide injection prefilled pen, which is used to treat severe osteoporosis. The injection was deemed bioequivalent and therapeutically equivalent to Eli Lilly's Forteo.
The company also has a long-standing share-repurchase program, having bought back over 14.1 million shares for about $369.1 million since 2016. Investors often view share buybacks as a positive sign that the company has extra capital and believes the stock is undervalued. Companies also sometimes buy back shares to offset the dilution caused by employee stock-option plans, like the one Petersen executed last month.
Glossary
Form 4: A required SEC filing disclosing insider trades of company stock by officers, directors, or large shareholders.
Option exercise: The act of converting stock options into actual company shares, typically at a predetermined price.
Vested stock options: Stock options that have met required conditions and are eligible to be exercised by the holder.
Open market: A public financial market where securities are bought and sold between investors, not directly from the issuing company.
Disposition: The act of selling or otherwise transferring ownership of an asset, such as company shares.
Direct ownership: Shares held personally by an individual, not through trusts or other indirect means.
Weighted average purchase price: The average price paid per share, calculated by weighting each purchase by the number of shares bought.
Median sell-only transaction: The middle value of all insider sales (excluding purchases), used to compare transaction sizes.
Vertically integrated: A business model where a company controls multiple stages of production, from raw materials to finished products.
API (active pharmaceutical ingredient): The primary component in a drug that produces its intended effects.
Proprietary drugs: Medications developed and owned by a company, often protected by patents.
TTM: The 12-month period ending with the most recent quarterly report.