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Who owns Amphastar Pharmaceuticals (AMPH) stock

202 funds reported Amphastar Pharmaceuticals (AMPH) shares in their latest 13F filings, worth $633M in all. The largest holder is BlackRock ($105M). Last quarter 84 funds added to their stakes and 95 cut them.

Largest holders of AMPH (13F)Largest holders of AMPH (13F)BlackRock$105MVanguard Group$69.8MDimensional Fund Advisors LP$46.5MState Street$33.1MVanguard Capital Management LLC$29.9MAmerican Century Companies$23.7MMarshall Wace, LLP$21.5MGeode Capital Management, LLC$19.6MFuller & Thaler Asset Management$19.2MD. E. Shaw$17.9M

Largest holders (13F)

FundSharesValueChangeQuarter
BlackRock5,224,934$105Mdecrease2026-06-30
Vanguard Group2,608,158$69.8Mdecrease2025-12-31
Dimensional Fund Advisors LP2,305,107$46.5Mincrease2026-06-30
State Street1,642,126$33.1Mincrease2026-06-30
Vanguard Capital Management LLC1,481,952$29.9Mdecrease2026-06-30
American Century Companies1,176,626$23.7Mincrease2026-06-30
Marshall Wace, LLP1,066,322$21.5Mincrease2026-06-30
Geode Capital Management, LLC969,840$19.6Mdecrease2026-06-30
Fuller & Thaler Asset Management949,238$19.2Mdecrease2026-06-30
D. E. Shaw887,048$17.9Mincrease2026-06-30
Vanguard Portfolio Management LLC809,568$16.3Mincrease2026-06-30
Mesirow Institutional Investment Management380,389$14.1Mdecrease2024-12-31
Renaissance Technologies LLC525,100$10.6Mdecrease2026-06-30
Goldman Sachs Group505,360$10.2Mincrease2026-06-30
Bridge City Capital, LLC383,901$9.9Mincrease2026-09-30

Amphastar Pharmaceuticals' latest quarter

Amphastar Pharmaceuticals, Q3 2026: revenue $208M (+8% year over year), operating margin 24.5%, net earnings $37.8M, operating cash flow $43.3M. The chart follows the revenue to costs, profit and cash.

Questions

Who owns the most AMPH stock?

By the latest 13F filings: BlackRock ($105M); Vanguard Group ($69.8M); Dimensional Fund Advisors LP ($46.5M); State Street ($33.1M); Vanguard Capital Management LLC ($29.9M).

What is the short interest in AMPH?

4,333,767 shares were sold short at the 2026-10-15 settlement, -1.62% of the float.

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Updated Nov 8, 2026. Read automatically from SEC filings and public data; errors are possible. Not investment advice.