Amphastar Pharmaceuticals, Inc.
AMPH- Exchange
- Nasdaq
- Industry
- Pharmaceutical Preparations
- SEC CIK
- 0001297184
In the last 90 days, Amphastar Pharmaceuticals, Inc. insiders filed 0 open-market purchases and 5 sales; 212 institutions reported holding it in 13F filings for Q2 2026, worth $572.1M in total; no superinvestor holds it.
Holders of 5% or more of AMPH
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Amphastar Pharmaceuticals, Inc., largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| Zhang Jack Y. | 13G/A | 24.80%12.5M shares | – | Feb 7, 20251 filing | Feb 7, 2025 | SEC |
| BlackRock, Inc. | 13G/A | 11.50%5.33M shares | – | Oct 17, 20251 filing | Oct 17, 2025 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
2 Schedule 13D and 13G filings on Amphastar Pharmaceuticals, Inc., newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Oct 17, 20254:05 PM ET | BlackRock, Inc. | 13G/A | 11.50%5.33M shares | – | Sep 30, 2025 | SEC |
| Feb 7, 20257:21 PM ET | Zhang Jack Y.and 2 others | 13G/A | 24.80%12.5M shares | – | Dec 31, 2024 | SEC |
Form 144: proposed insider sales
Notices from officers, directors and other affiliates planning to sell Amphastar Pharmaceuticals, Inc. shares.
No Form 144 notices for Amphastar Pharmaceuticals, Inc. are on file.