1. Amphastar Pharmaceuticals Inc
  2. Amphastar Pharmaceuticals Inc Ownership

Historical shareholding details of Oberweis Asset Management Inc holdings in Amphastar Pharmaceuticals Inc (AMPH)

Monthly changes of Oberweis Asset Management Inc shareholding in Amphastar Pharmaceuticals Inc over the previous months

Month Name Total no. shares held Percent Holding
Mar 31, 2025 Oberweis Asset Management Inc 330,200 0.69%
Feb 28, 2025 Oberweis Asset Management Inc 330,200 0.69%
Jan 31, 2025 Oberweis Asset Management Inc 280,200 0.58%
Dec 31, 2024 Oberweis Asset Management Inc 184,595 0.39%
Dec 31, 2024 Oberweis Asset Management Inc 280,200 0.58%
Nov 30, 2024 Oberweis Asset Management Inc 280,200 0.58%
Oct 31, 2024 Oberweis Asset Management Inc 222,400 0.46%
Sep 30, 2024 Oberweis Asset Management Inc 161,155 0.34%
Sep 30, 2024 Oberweis Asset Management Inc 222,400 0.45%
Aug 31, 2024 Oberweis Asset Management Inc 222,400 0.45%
Jul 31, 2024 Oberweis Asset Management Inc 505,800 1.03%
Jun 30, 2024 Oberweis Asset Management Inc 135,055 0.28%
Jun 30, 2024 Oberweis Asset Management Inc 789,200 1.61%
May 31, 2024 Oberweis Asset Management Inc 789,200 1.61%
Apr 30, 2024 Oberweis Asset Management Inc 637,000 1.30%
Mar 31, 2024 Oberweis Asset Management Inc 417,865 0.85%
Mar 31, 2024 Oberweis Asset Management Inc 637,000 1.30%
Feb 29, 2024 Oberweis Asset Management Inc 637,000 1.32%
Jan 31, 2024 Oberweis Asset Management Inc 305,000 0.64%
Dec 31, 2023 Oberweis Asset Management Inc 305,000 0.64%
Nov 30, 2023 Oberweis Asset Management Inc 300,300 0.63%
Oct 31, 2023 Oberweis Asset Management Inc 300,300 0.61%
Sep 30, 2023 Oberweis Asset Management Inc 152,500 0.31%
Sep 30, 2023 Oberweis Asset Management Inc 295,600 0.61%
Aug 31, 2023 Oberweis Asset Management Inc 336,200 0.69%
Jul 31, 2023 Oberweis Asset Management Inc 356,400 0.74%
Jun 30, 2023 Oberweis Asset Management Inc 147,800 0.30%
Jun 30, 2023 Oberweis Asset Management Inc 356,400 0.74%
May 31, 2023 Oberweis Asset Management Inc 268,000 0.56%
Mar 31, 2023 Oberweis Asset Management Inc 178,200 0.37%
Dec 31, 2022 Oberweis Asset Management Inc 134,000 0.28%

View all ownership details of Amphastar Pharmaceuticals Inc