WallStreetZenWallStreetZen

NASDAQ: AMPH
Amphastar Pharmaceuticals Inc Stock Ownership - Who owns Amphastar Pharmaceuticals?

OverviewForecastEarningsRevenueDividendOwnership

Insider buying vs selling

Have Amphastar Pharmaceuticals Inc insiders been buying or selling?

Buy
Sell
NameRoleDateSharesPriceValue
Rong ZhouSENIOR EVP PRODUCTION CENTER2025-12-179,787$26.20
$256.38kSell
Rong ZhouSENIOR EVP PRODUCTION CENTER2025-12-179,787$11.33
$110.89kBuy
Floyd F. PetersenDirector2025-12-122,426$25.92
$62.89kSell
Floyd F. PetersenDirector2025-12-111,737$25.69
$44.62kSell
Richard K. PrinsDirector2025-11-254,179$16.69
$69.75kBuy
Richard K. PrinsDirector2025-11-254,179$27.10
$113.26kSell
Floyd F. PetersenDirector2025-11-1316,679$26.49
$441.84kSell
Floyd F. PetersenDirector2025-11-1316,679$16.69
$278.37kBuy
Floyd F. PetersenDirector2025-11-03500$25.27
$12.63kSell
Floyd F. PetersenDirector2025-10-01500$27.21
$13.60kSell

1 of 5

AMPH insiders have bought more... subscribe to Premium to read more.
Net Insider Buy/Sell (L12M) Ownership

Be the first to know when AMPH insiders and whales buy or sell their stock.

AMPH Shareholders

What type of owners hold Amphastar Pharmaceuticals Inc stock?

Institutional
Insider
Retail
NameHoldSharesValueType
Jack Y. Zhang38.11%17,511,932$494.54MInsider
Mary Z. Luo19.46%8,941,010$252.49MInsider
Applied Physics Chemistry Laboratories Inc15.95%7,327,679$206.93MInsider
Blackrock Inc11.94%5,485,057$154.90MInstitution
Vanguard Group Inc5.73%2,631,040$74.30MInstitution
Td Asset Management Inc4.20%1,931,892$54.56MInstitution
Dimensional Fund Advisors LP3.82%1,755,665$49.58MInstitution
State Street Corp3.27%1,500,742$42.38MInstitution
Fuller Thaler Asset Management Inc2.95%1,353,927$38.23MInstitution
Boston Trust Walden Corp2.55%1,173,107$33.13MInstitution

1 of 3

AMPH vs Pharmaceutical Stocks

TickerInst. %Insider %Net Insider (L12M)Net Insider (L3M)
AMPH48.29%51.71%Net BuyingNet Selling
EVO5.56%0.00%
COLL51.95%48.05%Net SellingNet Selling
ALVO5.08%0.00%
CRON13.26%49.08%Net SellingNet Selling
View Top Pharmaceutical Stocks

Amphastar Pharmaceuticals Stock Ownership FAQ

Who owns Amphastar Pharmaceuticals?

Amphastar Pharmaceuticals (NASDAQ: AMPH) is owned by 71.26% institutional shareholders, 76.31% Amphastar Pharmaceuticals insiders, and 0.00% retail investors. Jack Y. Zhang is the largest individual Amphastar Pharmaceuticals shareholder, owning 17.51M shares representing 38.11% of the company. Jack Y. Zhang's Amphastar Pharmaceuticals shares are currently valued at $501.02M.

If you're new to stock investing, here's how to buy Amphastar Pharmaceuticals stock.
©2026 WallStreetZen
Company
AboutNewsBlogStock Investing FAQPlansPrivacy PolicyTerms of ServiceCancellation & RefundsPerformanceHelp GuidesContactTwitterYouTubeNewsletter
Stock Tools
Top Performing AnalystsStock ScreenerStock ForecastTrending StocksStrong Buy StocksHighest Earnings StocksBest Dividend Paying StocksStatisticsStock Market SectorsStock Market IndustriesHow to Buy Stocks Online
Stock Ideas
Buy The DipBiggest Stock Gainers TodayBiggest Stock Losers Today52 Week High Stocks52 Week Low StocksMost Active Stocks TodayMost Undervalued StocksBest Penny Stocks to Buy NowBest Stocks Under $5Best Stocks Under $10
WallStreetZen does not provide financial advice and does not issue recommendations or offers to buy stock or sell any security.

Information is provided 'as-is' and solely for informational purposes and is not advice. WallStreetZen does not bear any responsibility for any losses or damage that may occur as a result of reliance on this data.