StockCIK 1297184

Amphastar Pharmaceuticals, Inc. (AMPH): Insider Trades and Fund Holdings

In the past 12 months, Amphastar Pharmaceuticals, Inc. insiders reported 0 open-market purchases worth $0 and 3 sales worth $418K; 1 of the sales were reported as made under a 10b5-1 trading plan.

0Insider buys, 12 months

$0Bought by insiders, 12 months

$418KSold by insiders, 12 months

1Tracked funds holding

Recent insider trades

Open-market purchases (code P) and sales (code S) from Form 4. Grants, option exercises and gifts are not shown. Latest filing: Sep 23, 2026.

Recent AMPH insider trades
Filed	Traded	Insider	Role	Type	Shares	Price ($)	Value	Holding	Filing
Sep 23	Sep 21	William J. PetersCFO	CFO	▼ SELL10b5-1	4,139	25.00	$103K	−2.4%	Form 4 ↗
Sep 17	Sep 16	Rong ZhouEVP	EVP	▼ SELL	10,000	23.94	$239K	−5.6%	Form 4 ↗
Sep 3	Sep 2	Rong ZhouEVP	EVP	▼ SELL	3,187	23.63	$75K	−1.8%	Form 4 ↗

Source: SEC Form 4 filings, retrieved Oct 28, 2026. How we read filings

Insiders who traded in the past year

Insider	Role	Buys	Bought	Sells	Sold	Latest
William J. Peters	CFO	0	$0	1	$103K	Sep 23, 2026
Rong Zhou	EVP	0	$0	2	$315K	Sep 17, 2026

Tracked funds that report AMPH

From each fund's latest 13F. Holdings are as of quarter end and are filed up to 45 days later.

Fund	Quarter	Shares	Value	% of portfolio	Change
Renaissance Technologies	Q2 2026	525,100	$10.6M	0.01%	▼ −5.2%

Source: SEC Form 13F-HR filings, retrieved Oct 28, 2026. How we read filings

Reading these numbers

Insiders sell for many reasons: taxes, diversification, a house. Purchases with their own money are rarer and are usually read as more informative. A Form 4 is due within two business days of the trade. How to read a Form 4 →