Amphastar Pharmaceuticals, Inc. Insider Trading Activity
Every SEC Form 4 insider transaction reported for Amphastar Pharmaceuticals, Inc. (AMPH), sourced directly from SEC EDGAR and updated as new filings are accepted.
By Trabud · Insider-trading data from SEC EDGAR
Latest filing:
Compiled automatically from SEC EDGAR Form 4 filings and refreshed daily. Figures count purchases (code P) and sales (code S) only — not grants, option exercises, or gifts. How this page is built. Not investment advice.
Quick Answer
Are AMPH insiders buying or selling?
In the last 12 months, Amphastar Pharmaceuticals, Inc. insiders reported 0 open-market purchases ($0) and 10 sales ($1.7M) — net selling of $1.7M. Since January 2018, Trabud has recorded 240 Form 4 filings for AMPH: 2 buys ($663.1K) and 238 sells ($107.5M).
Source: SEC EDGAR Form 4
What stands out
- No Amphastar Pharmaceuticals, Inc. insider made an open-market purchase in the last 12 months; the 10 reported open-market sales totaled $1.7M.
Key Statistics (January 2018 – Sep 23, 2026)
Total Form 4 filings
240
SEC EDGAR
Insider filers
16
Insider buys (2)
$663.1K
Insider sells (238)
$107.5M
Insider sentiment
Net sellingNet insider flow of $106.8M in net selling since January 2018, and $1.7M in net selling over the last 12 months.
Recent AMPH insider transactions
| Date | Insider | Role | Type | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|
| Sep 23, 2026 | William J Peters | CFO, EVP & TREASURER | Sale | 4.1K | $25.00 | $103.5K | SEC ↗ |
| Sep 17, 2026 | Rong Zhou | SENIOR EVP, PRODUCTION CENTER | Sale | 10.0K | $23.94 | $239.4K | SEC ↗ |
| Sep 3, 2026 | Rong Zhou | SENIOR EVP, PRODUCTION CENTER | Sale | 3.2K | $23.63 | $75.3K | SEC ↗ |
| Aug 12, 2026 | Richard K Prins | Director | Sale | 8.0K | $20.30 | $161.9K | SEC ↗ |
| Aug 11, 2026 | William J Peters | CFO, EVP & TREASURER | Sale | 8.2K | $22.48 | $183.9K | SEC ↗ |
| Dec 18, 2025 | Rong Zhou | SENIOR EVP, PRODUCTION CENTER | Sale | 9.8K | $26.20 | $256.4K | SEC ↗ |
| Dec 15, 2025 | Floyd F. Petersen | Director | Sale | 4.2K | $25.82 | $107.5K | SEC ↗ |
| Nov 26, 2025 | Richard K Prins | Director | Sale | 4.2K | $27.10 | $113.3K | SEC ↗ |
| Nov 17, 2025 | Floyd F. Petersen | Director | Sale | 16.7K | $26.49 | $441.8K | SEC ↗ |
| Nov 5, 2025 | Floyd F. Petersen | Director | Sale | 500 | $25.27 | $12.6K | SEC ↗ |
| Oct 2, 2025 | Floyd F. Petersen | Director | Sale | 500 | $27.20 | $13.6K | SEC ↗ |
| Sep 3, 2025 | Floyd F. Petersen | Director | Sale | 500 | $30.98 | $15.5K | SEC ↗ |
| Aug 4, 2025 | Floyd F. Petersen | Director | Sale | 500 | $20.83 | $10.4K | SEC ↗ |
| Jul 3, 2025 | Floyd F. Petersen | Director | Sale | 500 | $23.47 | $11.7K | SEC ↗ |
| Jun 4, 2025 | Floyd F. Petersen | Director | Sale | 500 | $25.67 | $12.8K | SEC ↗ |
| May 3, 2025 | Floyd F. Petersen | Director | Sale | 500 | $24.08 | $12.0K | SEC ↗ |
| Apr 2, 2025 | Floyd F. Petersen | Director | Sale | 500 | $28.38 | $14.2K | SEC ↗ |
| Mar 7, 2025 | Floyd F. Petersen | Director | Sale | 1.0K | $27.99 | $28.0K | SEC ↗ |
| Mar 6, 2025 | William J Peters | CFO, EVP & TREASURER | Sale | 4.2K | $27.54 | $116.5K | SEC ↗ |
| Dec 16, 2024 | Rong Zhou | SENIOR EVP, PRODUCTION CENTER | Sale | 15.0K | $44.85 | $672.8K | SEC ↗ |
| Dec 12, 2024 | Richard K Prins | Director | Sale | 10.0K | $43.77 | $437.7K | SEC ↗ |
| Nov 14, 2024 | Rong Zhou | SENIOR EVP, PRODUCTION CENTER | Sale | 6.9K | $48.88 | $336.9K | SEC ↗ |
| Nov 13, 2024 | Richard K Prins | Director | Sale | 5.0K | $48.80 | $244.0K | SEC ↗ |
| Nov 9, 2024 | Yakob Liawatidewi | EVP CORP ADMIN CENTER | Sale | 5.2K | $52.05 | $271.4K | SEC ↗ |
| Nov 8, 2024 | William J Peters | CFO, EVP & TREASURER | Sale | 7.4K | $52.05 | $386.5K | SEC ↗ |
Showing the 25 most recent of 240 Form 4 filings for Amphastar Pharmaceuticals, Inc..
Most active AMPH insiders
- Floyd F. Petersen61 filings
- William J Peters48 filings
- Rong Zhou25 filings
- Richard K Prins24 filings
- Yakob Liawatidewi23 filings
Ask anything about AMPH insider activity
Use Trabud's AI agent to query Amphastar Pharmaceuticals, Inc.'s Form 4 history in plain English — "Show me AMPH CEO purchases this year" or compare it against any other ticker.
Open the AI agentAMPH insider trading FAQ
Are Amphastar Pharmaceuticals, Inc. insiders buying or selling?
In the last 12 months, Amphastar Pharmaceuticals, Inc. insiders reported 0 open-market purchases ($0) and 10 sales ($1.7M) — net selling of $1.7M. Since January 2018, Trabud has recorded 240 Form 4 filings for AMPH: 2 buys ($663.1K) and 238 sells ($107.5M). Over the full record that is net selling of $106.8M.
How many insiders trade AMPH stock?
16 distinct insider filers — officers, directors, 10%+ owners, and investment groups filing jointly — have reported Form 4 transactions for Amphastar Pharmaceuticals, Inc.. The most recent filing was accepted on Sep 23, 2026.
Where does Trabud get AMPH insider trading data?
All AMPH insider trading data comes directly from official SEC EDGAR Form 4 filings, which corporate insiders must submit within two business days of a transaction under Section 16(a) of the Securities Exchange Act of 1934.