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AMPHASTAR PHARMACEUTICALS IN (AMPH) Stock Ownership and Short Interest

USA - Nasdaq - NASDAQ:AMPH - US03209R1032 - Common Stock

27.67 USD
+0.31 (+1.13%)
Last: 11/28/2025, 11:53:03 AM
AMPH Ownership Chart.AMPH Ownership Chart: showing Insider, Institutional ownership and shares available to the public.AMPH Ownership.InsiderInstitutionalPublic



Shares Outstanding46.50M
Float35.33M
Float Short Interest Percentage11.87%
Owners (insider)9.28%
Owners (institutional)71.91%
Owners (insider) change3.46%
Owners (institutional) change0.4%
AMPH Institutional Ownership HistoryAMPH Institutional Ownership HistoryAMPH Institutional Ownership History Sep 2021 Mar 2022 Sep 2022 Mar 2023 Sep 2023 Mar 2024 Sep 2024 Mar 2025 Sep 2025 10M 20M 30M
AMPH Historical Insider Transactions ChartAMPH Historical Insider Buy and Sell Transactions ChartAMPH Historical Insider Transactions Dec 2024 Jan 2025 Feb 2025 Mar 2025 Apr 2025 May 2025 Jun 2025 Jul 2025 Aug 2025 Sep 2025 Oct 2025 Nov 2025 0 100K 200K 300K 400K 500K
Date Name Type Shares Price Amount
Nov 25, 2025 PRINS RICHARD K Option Excercise 4179 16.69 $ 69,747.51
Nov 25, 2025 PRINS RICHARD K Open Market Sale 4179 27.10 $ 113,253.41
Nov 13, 2025 Petersen Floyd F. Option Excercise 16679 16.69 $ 278,372.51
Nov 13, 2025 Petersen Floyd F. Open Market Sale 16679 26.49 $ 441,836.72
Nov 3, 2025 Petersen Floyd F. Open Market Sale 500 25.27 $ 12,633.10
Oct 1, 2025 Petersen Floyd F. Open Market Sale 500 27.20 $ 13,602.40
Sep 2, 2025 Petersen Floyd F. Open Market Sale 500 30.98 $ 15,491.65
Aug 1, 2025 Petersen Floyd F. Open Market Sale 500 20.83 $ 10,415.75
Jul 18, 2025 Gaugh David Russell Grant 6304 0.00 $ 0.00
Jul 2, 2025 Petersen Floyd F. Open Market Sale 500 23.47 $ 11,733.95
Jun 13, 2025 Zhang Jack Y. Option Excercise 200000 13.03 $ 2,606,000.00
Jun 13, 2025 Luo Mary Z. Option Excercise 200000 13.03 $ 2,606,000.00
Jun 3, 2025 Lee Howard Option Excercise 923 26.01 $ 24,007.23
Jun 2, 2025 Gerst Diane G. Grant 5122 0.00 $ 0.00
Jun 2, 2025 Deflin Gayle Grant 5122 0.00 $ 0.00
Jun 2, 2025 Lee Howard Grant 5122 0.00 $ 0.00
May 19, 2025 PETERS WILLIAM J Option Excercise 273 24.79 $ 6,767.67
May 1, 2025 Petersen Floyd F. Open Market Sale 500 24.08 $ 12,041.45
Mar 15, 2025 Liawatidewi Yakob Option Excercise 2762 27.31 $ 75,417.85
Mar 15, 2025 PETERS WILLIAM J Option Excercise 4972 27.28 $ 135,647.64
Mar 15, 2025 Zhou Rong Option Excercise 3189 27.30 $ 87,044.75
Mar 14, 2025 Zhang Jack Y. Option Excercise 501690 14.69 $ 7,369,826.10
Mar 14, 2025 Luo Mary Z. Option Excercise 501690 14.69 $ 7,369,826.10
Mar 14, 2025 Zhang Jack Y. Option Excercise 426195 26.72 $ 11,386,432.89
Mar 14, 2025 Luo Mary Z. Option Excercise 426195 26.72 $ 11,386,432.89
Mar 10, 2025 Luo Mary Z. Grant 165222 0.00 $ 0.00
Mar 10, 2025 Liawatidewi Yakob Grant 20837 0.00 $ 0.00
Mar 10, 2025 PETERS WILLIAM J Grant 36747 0.00 $ 0.00
Mar 10, 2025 Zhou Rong Grant 24692 0.00 $ 0.00
Mar 10, 2025 Zhang Jack Y. Grant 165222 0.00 $ 0.00
Mar 6, 2025 Petersen Floyd F. Open Market Sale 1000 27.99 $ 27,986.30
Mar 6, 2025 Liawatidewi Yakob Option Excercise 1141 28.32 $ 32,313.12
Mar 6, 2025 Zhang Jack Y. Option Excercise 12714 28.32 $ 360,060.48
Mar 6, 2025 Luo Mary Z. Option Excercise 12714 28.32 $ 360,060.48
Mar 6, 2025 PETERS WILLIAM J Option Excercise 2141 28.32 $ 60,633.12
Mar 6, 2025 Zhou Rong Option Excercise 1354 28.32 $ 38,345.28
Mar 4, 2025 Zhou Rong Option Excercise 1121 27.62 $ 30,962.02
Mar 4, 2025 Liawatidewi Yakob Option Excercise 963 27.62 $ 26,598.06
Mar 4, 2025 Zhang Jack Y. Option Excercise 8179 27.62 $ 225,903.98
Mar 4, 2025 Luo Mary Z. Option Excercise 8179 27.62 $ 225,903.98
Mar 4, 2025 PETERS WILLIAM J Option Excercise 7490 13.35 $ 99,991.50
Mar 4, 2025 PETERS WILLIAM J Open Market Sale 4231 27.54 $ 116,515.39
Mar 4, 2025 PETERS WILLIAM J Option Excercise 1739 27.62 $ 48,031.18
Dec 12, 2024 Zhou Rong Option Excercise 15000 11.33 $ 169,950.00
Dec 12, 2024 Zhou Rong Open Market Sale 15000 44.85 $ 672,815.00
Dec 9, 2024 PRINS RICHARD K Option Excercise 10000 19.52 $ 195,200.00
Dec 9, 2024 PRINS RICHARD K Open Market Sale 10000 43.77 $ 437,702.00
Dec 9, 2024 PRINS RICHARD K Other Disposition 410 0.00 $ 0.00