Jack Y. Zhang
CIK: 0001611157
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 (28 total)
- Mar 15, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Indirect2.9K shares at avg. $18.18$53K - Mar 15, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct9.8K shares at avg. $18.18$178K - Mar 10, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Indirect4.4K shares at avg. $18.91$83K - Mar 10, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct14.8K shares at avg. $18.91$280K - Mar 9, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Award(A)Direct180.5K shares- - Mar 9, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Award(A)Indirect72.5K shares- - Mar 6, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Indirect3.1K shares at avg. $19.34$60K - Mar 6, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct7.8K shares at avg. $19.34$150K - Mar 4, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Indirect2.4K shares at avg. $19.96$49K - Mar 4, 2026AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct5.8K shares at avg. $19.96$115K - Jun 13, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Exercise(M)Direct200K shares at avg. $13.03$2.6M - Mar 17, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct16.2K shares at avg. $27.69$447K - Mar 17, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Indirect7.2K shares at avg. $27.69$200K - Mar 15, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct9.8K shares at avg. $26.66$260K - Mar 15, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Indirect4.1K shares at avg. $26.66$110K - Mar 14, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct226.3K shares at avg. $26.66$6.0M - Mar 14, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Exercise(M)Indirect211.2K shares at avg. $14.69$3.1M - Mar 14, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Indirect162.7K shares at avg. $26.66$4.3M - Mar 14, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Exercise(M)Direct290.5K shares at avg. $14.69$4.3M - Mar 10, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Award(A)Indirect49K shares- - Mar 10, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Award(A)Direct116.2K shares- - Mar 6, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct9.6K shares at avg. $28.32$273K - Mar 6, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Indirect3.1K shares at avg. $28.32$87K - Mar 4, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Indirect2.4K shares at avg. $27.62$67K - Mar 4, 2025AMPH
Amphastar Pharmaceuticals, Inc.
Tax Payment(F)Direct5.8K shares at avg. $27.62$159K
| Type | Shares | Price | Ownership | |||
|---|---|---|---|---|---|---|
| Mar 15, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 2,908 | $18.18 | $52,867 | Indirect |
| Mar 15, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 9,784 | $18.18 | $177,873 | Direct |
| Mar 10, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 4,395 | $18.91 | $83,109 | Indirect |
| Mar 10, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 14,785 | $18.91 | $279,584 | Direct |
| Mar 9, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Award(A) | 180,504 | - | $0 | Direct |
| Mar 9, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Award(A) | 72,462 | - | $0 | Indirect |
| Mar 6, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 3,077 | $19.34 | $59,509 | Indirect |
| Mar 6, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 7,773 | $19.34 | $150,330 | Direct |
| Mar 4, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 2,432 | $19.96 | $48,543 | Indirect |
| Mar 4, 2026 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 5,769 | $19.96 | $115,149 | Direct |
| Jun 13, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Exercise(M) | 200,000 | $13.03 | $2,606,000 | Direct |
| Mar 17, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 16,150 | $27.69 | $447,194 | Direct |
| Mar 17, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 7,223 | $27.69 | $200,005 | Indirect |
| Mar 15, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 9,765 | $26.66 | $260,335 | Direct |
| Mar 15, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 4,115 | $26.66 | $109,706 | Indirect |
| Mar 14, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 226,285 | $26.66 | $6,032,758 | Direct |
| Mar 14, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Exercise(M) | 211,213 | $14.69 | $3,102,719 | Indirect |
| Mar 14, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 162,657 | $26.66 | $4,336,436 | Indirect |
| Mar 14, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Exercise(M) | 290,477 | $14.69 | $4,267,107 | Direct |
| Mar 10, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Award(A) | 48,996 | - | - | Indirect |
| Mar 10, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Award(A) | 116,226 | - | - | Direct |
| Mar 6, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 9,645 | $28.32 | $273,146 | Direct |
| Mar 6, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 3,069 | $28.32 | $86,914 | Indirect |
| Mar 4, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 2,426 | $27.62 | $67,006 | Indirect |
| Mar 4, 2025 | AMPH Amphastar Pharmaceuticals, Inc. | Tax Payment(F) | 5,753 | $27.62 | $158,898 | Direct |
1-25 of 28 transactions
About Zhang Jack Y.
Zhang Jack Y. (SEC CIK 0001611157) files insider reports with the SEC as CEO & CHIEF SCIENTIFIC OFFICER of Amphastar Pharmaceuticals, Inc. (AMPH).
Signal8 holds 11 ownership filings by Zhang Jack Y., all Form 4s, filed between Sep 16, 2024 and Mar 17, 2026. Those filings report 28 transactions, from Sep 13, 2024 to Mar 15, 2026. Signal8's Form 4 history starts in Sep 2024.
The business address on Zhang Jack Y.'s filings is in RANCHO CUCAMONGA, CA.
Recent filings by Zhang Jack Y.
- Mar 15, 2026: Tax withholdings of AMPH shares (2 lines, Form 4, code F).
- Mar 10, 2026: Tax withholdings of AMPH shares (2 lines, Form 4, code F).
- Mar 9, 2026: Grants or awards of AMPH shares (2 lines, Form 4, code A).
- Mar 6, 2026: Tax withholdings of AMPH shares (2 lines, Form 4, code F).
- Mar 4, 2026: Tax withholdings of AMPH shares (2 lines, Form 4, code F).
Other insiders filing for Amphastar Pharmaceuticals, Inc. (AMPH)
- PETERS WILLIAM J, CFO, EVP & TREASURER
- Zhou Rong, SENIOR EVP, PRODUCTION CENTER
- PRINS RICHARD K, Director
- Pierce Anthony T, Director
- Lee Howard, Director
- ZASLOFF MICHAEL A, Director