// company-profile

Amphastar Pharmaceuticals, Inc.

AMPH
ExchangeNasdaqSectorPharmaceutical PreparationsFilings143Insiders12
// api This Amphastar Pharmaceuticals, Inc. insider-trading data is served live by the Form4API insider trading API. Get the same data via API.

// activity-summary

Recent insider activity is bullish. Over the last 30 days, 10 insiders purchased shares versus 1 sale. Buying was led by Gerst Diane G..

// 90-day insight

Over the last 90 days, Amphastar Pharmaceuticals, Inc. insiders bought $0 (10 transactions) and sold $14K (1 transaction).

  • Most active insider: Lee Howard with 3 transactions totaling $14K.
  • Largest single sale: $14K by Lee Howard on Jun 2, 2026.

Activity skews bullish — buys outpace sales.

Institutional Ownership

Top 13F-HR holders of Amphastar Pharmaceuticals, Inc. as of 2026-03-31

↓ decreasing
Total reported AUM
$583.9M
QoQ change
-20.3%
Reporting period
2026-03-31
#1
BlackRock, Inc.
CIK 2012383
$76.0M
3.9M shares
#2
DIMENSIONAL FUND ADVISORS LP
CIK 354204
$38.2M
2.0M shares
#3
STATE STREET CORP
CIK 93751
$31.5M
1.6M shares

Data source: SEC Form 13F-HR filings. Joined with insider activity above — see who's loading up institutionally while insiders are trading. Full 13F-HR API →

Insider Transactions

Sourced from SEC EDGAR Form 4 filings. Updated hourly.

DateInsiderCompanyTypeSharesPriceValue
Jun 2, 2026Lee HowardAMPH
Tax Withholding
769$18.45$14K
Jun 1, 2026Gerst Diane G.AMPH
Award
8,143$0.00$0K
Jun 1, 2026Lee HowardAMPH
Award
8,143$0.00$0K
Jun 1, 2026Gerst Diane G.AMPH
Award
17,365$0.00$0K
Jun 1, 2026ZASLOFF MICHAEL AAMPH
Award
17,365$0.00$0K

45 more transactions hidden

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