William J. Peters
CIK: 0001263136
Transaction Breakdown
High conviction signal
Position reduction
Derivative conversions
Compensation grants
Gifts, tax withholding, conversions, dispositions to the issuer and other codes
Companies & Roles (1)
Amphastar Pharmaceuticals, Inc.
Discretionary Trading P&L
Holdings
Transaction History (18 total)
- Sep 21, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Sale(S)Direct4.1K shares at avg. $25.00$103K - Aug 7, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Sale(S)Direct8.2K shares at avg. $22.48$184K - Aug 7, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Exercise(M)Direct5.1K shares at avg. $19.79$100K - Mar 15, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct2K shares at avg. $18.18$36K - Mar 10, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct3.3K shares at avg. $18.91$62K - Mar 9, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Award(A)Direct58.7K shares- - Mar 6, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct2.1K shares at avg. $19.34$42K - Mar 4, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct1.7K shares at avg. $19.96$35K - May 19, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct273 shares at avg. $24.79$7K - Mar 17, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct3K shares at avg. $27.69$83K - Mar 15, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct2K shares at avg. $26.66$52K - Mar 10, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Award(A)Direct36.7K shares- - Mar 6, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct2.1K shares at avg. $28.32$61K - Mar 4, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct1.7K shares at avg. $27.62$48K - Mar 4, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Exercise(M)Direct7.5K shares at avg. $13.35$100K - Mar 4, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Sale(S)Direct4.2K shares at avg. $27.54$117K - Nov 6, 2024AMPH
Amphastar Pharmaceuticals, Inc.
Sale(S)Direct7.4K shares at avg. $52.05$387K - Nov 6, 2024AMPH
Amphastar Pharmaceuticals, Inc.
Exercise(M)Direct7.4K shares at avg. $13.03$97K
| Type | Shares | Price | Ownership | |||
|---|---|---|---|---|---|---|
| Sep 21, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Sale(S) | 4,139 | $25.00 | $103,475 | Direct |
| Aug 7, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Sale(S) | 8,180 | $22.48 | $183,886 | Direct |
| Aug 7, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Exercise(M) | 5,053 | $19.79 | $99,999 | Direct |
| Mar 15, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 1,973 | $18.18 | $35,869 | Direct |
| Mar 10, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 3,297 | $18.91 | $62,346 | Direct |
| Mar 9, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Award(A) | 58,693 | - | $0 | Direct |
| Mar 6, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 2,146 | $19.34 | $41,504 | Direct |
| Mar 4, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 1,744 | $19.96 | $34,810 | Direct |
| May 19, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 273 | $24.79 | $6,768 | Direct |
| Mar 17, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 3,004 | $27.69 | $83,181 | Direct |
| Mar 15, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 1,968 | $26.66 | $52,467 | Direct |
| Mar 10, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Award(A) | 36,747 | - | - | Direct |
| Mar 6, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 2,141 | $28.32 | $60,633 | Direct |
| Mar 4, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 1,739 | $27.62 | $48,031 | Direct |
| Mar 4, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Exercise(M) | 7,490 | $13.35 | $99,992 | Direct |
| Mar 4, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Sale(S) | 4,231 | $27.54 | $116,515 | Direct |
| Nov 6, 2024 | AMPH Amphastar Pharmaceuticals, Inc. | Sale(S) | 7,426 | $52.05 | $386,523 | Direct |
| Nov 6, 2024 | AMPH Amphastar Pharmaceuticals, Inc. | Exercise(M) | 7,426 | $13.03 | $96,761 | Direct |
1-18 of 18 transactions
About PETERS WILLIAM J
PETERS WILLIAM J (SEC CIK 0001263136) files insider reports with the SEC as CFO, EVP & TREASURER of Amphastar Pharmaceuticals, Inc. (AMPH).
Signal8 holds 12 ownership filings by PETERS WILLIAM J, all Form 4s, filed between Nov 8, 2024 and Sep 23, 2026. Those filings report 18 transactions, from Nov 6, 2024 to Sep 21, 2026. Signal8's Form 4 history starts in Sep 2024.
The business address on PETERS WILLIAM J's filings is in RANCHO CUCAMONGA, CA.
Recent filings by PETERS WILLIAM J
- Sep 21, 2026: Open-market sale of AMPH shares (Form 4, code S).
- Aug 7, 2026: Open-market sale of AMPH shares (Form 4, code S).
- Aug 7, 2026: Option exercise of AMPH shares (Form 4, code M).
- Mar 15, 2026: Tax withholding of AMPH shares (Form 4, code F).
- Mar 10, 2026: Tax withholding of AMPH shares (Form 4, code F).
Other insiders filing for Amphastar Pharmaceuticals, Inc. (AMPH)
- Zhou Rong, SENIOR EVP, PRODUCTION CENTER
- PRINS RICHARD K, Director
- Pierce Anthony T, Director
- Lee Howard, Director
- ZASLOFF MICHAEL A, Director
- Gerst Diane G., Director