Amphastar Pharmaceuticals, Inc. (AMPH) Holders & Ownership

Amphastar Pharmaceuticals, Inc. (AMPH) ownership: insiders 5% · institutions 65% · index and ETF funds 12% (13F 2026-03-31). Insider activity, 90 days: 2 sales, 0 open-market buys. SEC EDGAR first-party data.

Top Institutional Holders (13F, rolled up by parent)

Source: SEC Form 13F
HolderSharesMarket Value% OutstandingReported
BlackRock5421343.00$106.20M12.3%2026-03-31
Vanguard2655473.00$52.02M6.0%2026-03-31
Dimensional Fund Advisors2027947.00$39.73M4.6%2026-03-31
State Street1607515.00$31.49M3.6%2026-03-31
TD Asset Management1541044.00$30.19M3.5%2026-03-31
Fuller & Thaler Asset Management, Inc.1395139.00$27.33M3.2%2026-03-31
Marshall Wace1025640.00$20.09M2.3%2026-03-31
American Century1017538.00$19.93M2.3%2026-03-31

Insider Trading Activity (Form 4)

Source: SEC Form 4
InsiderTransactionValueDate
Sellnull2026-08-11
Sellnull2026-08-07
Sellnull2026-08-07
Sellnull2026-08-07
Sellnull2026-07-09
Sellnull2026-07-09
Buynull2026-06-02
Sellnull2026-06-01

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Institutional data from SEC Form 13F. Insider data from SEC Form 4. Congressional data from STOCK Act disclosures. Not personalized investment advice.