AMPHASTAR PHARMACEUTICALS IN (AMPH) Institutional Buying Activity

Institutional investors tracked by InsiderSet increased exposure to AMPHASTAR PHARMACEUTICALS IN (AMPH) during the quarter ended March 31, 2026 through a combination of new purchases and expanded existing positions disclosed in SEC Form 13F filings.

The largest institutional buyer of AMPH during the latest reporting period was Renaissance Technologies LLC, which increased its reported AMPH position by approximately $1.87M based on quarter-end filing values. Several additional hedge funds and long-term asset managers also reported meaningful increases in AMPH exposure during the quarter.

Institutional buying activity can provide insight into investor conviction, sector allocation trends, and smart money positioning toward AMPHASTAR PHARMACEUTICALS IN (AMPH). InsiderSet tracks quarterly accumulation trends, new institutional positions, ownership increases, and estimated performance of newly disclosed holdings using SEC filing data and recent market prices.

The investors highlighted on this page collectively added approximately $3.71M in reported AMPH exposure during the latest filing period, reflecting continued institutional interest in AMPHASTAR PHARMACEUTICALS IN's growth initiatives and strategic positioning.

Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q1 2026Renaissance Technologies LLCBuy9,200553,900$10,850,901
Q3 2025Renaissance Technologies LLCBuy10,400586,900$15,640,885
Q2 2025Renaissance Technologies LLCBuy81,500576,500$13,236,440
Q4 2024Renaissance Technologies LLCBuy36,100525,500$19,511,815
Q4 2023Renaissance Technologies LLCBuy38,800641,900$39,702
Q3 2023Renaissance Technologies LLCBuy110,517603,100$27,737
Q1 2023Renaissance Technologies LLCBuy49,400496,800$18,630
Q4 2022Renaissance Technologies LLCBuy13,600447,400$12,536
Q3 2022Renaissance Technologies LLCBuy26,900433,800$12,190
Q2 2022Renaissance Technologies LLCBuy98,200406,900$14,156
Q1 2022Renaissance Technologies LLCBuy18,900308,700$11,082
Q4 2021Renaissance Technologies LLCBuy14,100289,800$6,749
Q3 2021Renaissance Technologies LLCBuy28,600275,700$5,241
Q2 2021Renaissance Technologies LLCBuy21,500247,100$4,982
Q4 2019Renaissance Technologies LLCBuy102,300833,000$16,069
Q3 2019Renaissance Technologies LLCBuy142,700730,700$14,490
Q2 2019Renaissance Technologies LLCBuy146,400588,000$12,413
Q1 2019Renaissance Technologies LLCBuy131,500441,600$9,022
Q4 2018Renaissance Technologies LLCBuy124,000310,100$6,171
Q3 2018Renaissance Technologies LLCBuy134,500186,100$3,581
Q1 2018Renaissance Technologies LLCBuy39,80051,600$968
Q2 2015Renaissance Technologies LLCBuy193,626317,006$5,573
Q1 2015Renaissance Technologies LLCBuy123,380123,380$1,846

Frequently asked questions about AMPH activity

  • Which institutional owners are buying AMPH?

    Institutional owners buying AMPH include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.

  • What does "buy" mean in AMPH activity?

    "Buy" means an investor increased their reported position in AMPH compared to the prior reporting period. This reflects growing exposure to AMPHASTAR PHARMACEUTICALS IN (AMPH) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).

  • Is institutional interest in AMPH increasing?

    Institutional interest in AMPH can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.

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