NASDAQ:AMPH

Amphastar Pharmaceuticals Stock Insider Trading

Healthcare > Drug Manufacturers - Specialty & Generic

Buy AMPH

*Your capital is at risk

$19.94

-0.440 (-2.16%)

At Close: Jul 31, 2026

Amphastar Pharmaceuticals Stock Insider Power

Based on the 100 latest insides trades, we have calculated the insider power to be positive at 62.48. In total, the insiders bought 2.43M and sold 114.94K AMPH shares in the last 100 trades. The insider score can be negative despite buy/sell ratio being positive. The score focuses on the quality of the trades.

Insider Power (Last 100 transactions)	62.48
● Buy	2.43M shares
● Sell	114.94K shares
61% Buy Activity Strong Negative Correlation
Buy Signal Medium Confidence Mar 09, 2026 Analysis Breakdown: Strongly supported by a very high Insider Power Score of 62.48. Confidence increased due to high data reliability score of 100.

Historical Insider Trades

Date	Type	Person	Role	Amount
Dec 11, 2025 Sell	Common Stock S-Sale	Petersen Floyd F. Director	Director	1 737 Value: $44.6K
Nov 25, 2025 Buy	Common Stock M-Exempt	Prins Richard K Director	Director	4 179 Value: $69.7K
Nov 25, 2025 Sell	Common Stock S-Sale	Prins Richard K Director	Director	4 179 Value: $113.3K
Nov 25, 2025 Buy	Stock Option (right to buy) M-Exempt	Prins Richard K Director	Director	4 179 Value: $69.7K
Nov 13, 2025 Buy	Common Stock M-Exempt	Petersen Floyd F. Director	Director	16 679 Value: $278.4K
Nov 13, 2025 Sell	Common Stock S-Sale	Petersen Floyd F. Director	Director	16 679 Value: $441.8K
Nov 13, 2025 Buy	Stock Option (right to buy) M-Exempt	Petersen Floyd F. Director	Director	16 679 Value: $278.4K
Nov 03, 2025 Sell	Common Stock S-Sale	Petersen Floyd F. Director	Director	500 Value: $12.6K
Oct 01, 2025 Sell	Common Stock S-Sale	Petersen Floyd F. Director	Director	500 Value: $13.6K
Oct 01, 2025 Sell	Common Stock S-Sale	Petersen Floyd F. Director	Director	500 Value: $13.6K
Sep 02, 2025 Sell	Common Stock S-Sale	Petersen Floyd F. Director	Director	500 Value: $15.5K
Sep 02, 2025 Sell	Common Stock S-Sale	Petersen Floyd F. Director	Director	500 Value: $15.5K
Aug 01, 2025 Sell	Common Stock S-Sale	Petersen Floyd F. Director	Director	500 Value: $10.4K
Aug 01, 2025 Sell	Common Stock S-Sale	Petersen Floyd F. Director	Director	500 Value: $10.4K
Jul 18, 2025 Buy	Stock Option (right to buy) A-Award	Gaugh David Russell Director	Director	13 987 Value: $288.4K
Jul 18, 2025 Buy	Common Stock A-Award	Gaugh David Russell Director	Director	6 304 Value: $130.0K
Jul 18, 2025 Buy	Common Stock J-Other	Gaugh David Russell Insider	Other	0 Value: $0
Jul 18, 2025 Buy	Common Stock J-Other	Gaugh David Russell Insider	Other	0 Value: $0
Jul 18, 2025 Buy	Common Stock A-Award	Gaugh David Russell Director	Director	6 304 Value: $130.0K
Jul 18, 2025 Buy	Stock Option (right to buy) A-Award	Gaugh David Russell Director	Director	13 987 Value: $288.4K
Jul 02, 2025 Sell	Common Stock S-Sale	Petersen Floyd F. Director	Director	500 Value: $11.7K
Jul 02, 2025 Sell	Common Stock S-Sale	Petersen Floyd F. Director	Director	500 Value: $11.7K
Jun 13, 2025 Buy	Common Stock M-Exempt	Zhang Jack Y. CEO & Chief Scientific Officer	CEO / President	200 000 Value: $2.61M
Jun 13, 2025 Buy	Employee Stock Option (right to buy) M-Exempt	Zhang Jack Y. CEO & Chief Scientific Officer	CEO / President	200 000 Value: $2.61M
Jun 13, 2025 Buy	Employee Stock Option (right to buy) M-Exempt	Zhang Jack Y. CEO & Chief Scientific Officer	CEO / President	200 000 Value: $2.61M

About Insider Power

Insider Power is a proprietary algorithm developed by StockInvest.us to evaluate the significance of insider transactions. The calculation considers the size, type, and timing of transactions, as well as the insider’s role within the company.

It is important to note that, in general, there is little to no correlation between insider transactions and short-term stock price movements. In one of our studies, only 0.22%^* of stocks with insider activity showed a measurable correlation — and even then, it was unclear whether the effect was caused by insider actions or simply by the stock’s broader trend.

While our algorithms are designed to highlight potentially meaningful signals, these cannot be regarded as statistically significant on their own. Insider trading activity should therefore be seen as informative rather than as direct trading guidance. The Insider Power metric was created to present this information in a clearer and more accessible way, helping investors better understand the possible context of insider activity.

* October 6th, 2025 - Tested on 5562 stocks

ABOUT AMPHASTAR PHARMACEUTICALS

Amphastar Pharmaceuticals, Inc., a bio-pharmaceutical company, develops, manufactures, markets, and sells generic and proprietary injectable, inhalation, and intranasal products in the United States, China, and France. The company operates through two segments, Finished Pharmaceutical Products and API. It offers Primatene Mist, an over-the-counter epinephrine inhalation product for the temporary relief of mild symptoms of intermittent asthma; Eno...

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