Paydirt
AMPH
Ticker

Amphastar Pharmaceuticals, Inc.

AMPH · Healthcare · Amphastar Pharmaceuticals, Inc., a bio-pharmaceutical company, develops, manufactures, markets, and sells generic and proprietary injectabl…

Amphastar Pharmaceuticals, Inc. (AMPH), in the Healthcare sector, has 6 disclosed filings on Paydirt over the trailing twelve months from 4 corporate insiders: 0 purchases and 6 sales. Filers took a median of 1 day from execution to disclosure, and the most recent trade was executed Sep 16 and filed Sep 17. The most active filer was Richard K Prins with 4 filings.

Add to watchlist
Filings, ttm
6
0 buys · 6 sells
Traders, ttm
4
4 insiders
Volume, ttmiDollar value disclosed in the window
$1.4M
estimated for Congress, as filed for insiders
Median delay
1d
execution to disclosure
Last traded
Sep 16
Filed Sep 17
ADViAverage daily dollar volume
$12.0M
market data
Share price · 12M
$23.62 (-15.3%)
$29.40$23.14$16.87Sep 22 2025Mar 23Sep 18

Adjusted for splits and dividends.

Volume by month
$1.2M$619K$0Oct 2024Apr 2025Oct 2025Apr 2026Nov 2024 · sells $1.2MDec 2024 · sells $1.1MMar 2025 · sells $117KNov 2025 · sells $555KDec 2025 · sells $256KAug 2026 · sells $346KSep 2026 · sells $239K
Buys $0 Sells $3.9M

Estimated for Congress, as filed for insiders · by filing month · past 24 months

Who filed
RP Richard K Prins Director 4 filings RZ Rong Zhou SENIOR EVP, PRODUCTION CENTER 4 filings WP William J Peters CFO, EVP & TREASURER 3 filings YL Yakob Liawatidewi EVP CORP ADMIN CENTER 1 filing FP Floyd F. Petersen Director 1 filing
Recent filings
Rong ZhouSALE SENIOR EVP, PRODUCTION CENTER $239K
10,000 sh × $23.94
Exec Sep 16
Filed Sep 17 · 6:19 PM ET Richard K PrinsSALE Director $162K
7,973 sh × $20.30
Exec Aug 11
Filed Aug 12 · 6:14 PM ET William J PetersSALE CFO, EVP & TREASURER $184K
8,180 sh × $22.48
Exec Aug 7
Filed Aug 11 · 4:57 PM ET Rong ZhouSALE SENIOR EVP, PRODUCTION CENTER $256K
9,787 sh × $26.20
Exec Dec 17 2025
Filed Dec 18 2025 · 5:30 PM ET Richard K PrinsSALE Director $113K
4,179 sh × $27.10
Exec Nov 25 2025
Filed Nov 25 2025 · 5:30 PM ET Floyd F. PetersenSALE Director $442K
16,679 sh × $26.49
Exec Nov 13 2025
Filed Nov 17 2025 · 5:30 PM ET William J PetersSALE CFO, EVP & TREASURER $117K
4,231 sh × $27.54
Exec Mar 4 2025
Filed Mar 6 2025 · 5:30 PM ET Rong ZhouSALE SENIOR EVP, PRODUCTION CENTER $673K
15,000 sh across 2 lots
Exec Dec 12 2024
Filed Dec 16 2024 · 5:30 PM ET Richard K PrinsSALE Director $438K
10,000 sh × $43.77
Exec Dec 9 2024
Filed Dec 11 2024 · 5:30 PM ET Richard K PrinsSALE Director $244K
5,000 sh × $48.80
Exec Nov 12 2024
Filed Nov 13 2024 · 5:30 PM ET Rong ZhouSALE SENIOR EVP, PRODUCTION CENTER $337K
6,893 sh × $48.88
Exec Nov 12 2024
Filed Nov 13 2024 · 5:30 PM ET William J PetersSALE CFO, EVP & TREASURER $387K
7,426 sh × $52.05
Exec Nov 6 2024
Filed Nov 8 2024 · 5:30 PM ET Yakob LiawatidewiSALE EVP CORP ADMIN CENTER $271K
5,214 sh × $52.05
Exec Nov 6 2024
Filed Nov 8 2024 · 5:30 PM ET Rong ZhouSALE SENIOR EVP, PRODUCTION CENTER $145K
3,000 sh × $48.26
Exec Sep 13 2024
Filed Sep 17 2024 · 5:30 PM ET