Key facts
- This page summarizes Rong Zhou's Form 4 filing for Amphastar Pharmaceuticals, Inc. (AMPH).
- 1 reported transaction and 0 derivative rows are listed below.
- Accepted by SEC: 17 Mar 2026, 18:16.
Rong Zhou - 15 Mar 2026 Form 4 Insider Report for Amphastar Pharmaceuticals, Inc. (AMPH)
- Reporting relationship
- SENIOR EVP, PRODUCTION CENTER
- Issuer ticker
- AMPH
- Reported as of
- 15 Mar 2026
- Net transaction value
- $0
- SEC form
- 4
- Accepted by SEC
- 17 Mar 2026, 18:16:22 UTC
- Prior SEC filing
- 11 Mar 2026
- Source filing
- View source filing
- Reporting owner signature
- /s/ Eva Wen, by power of attorney
Source evidence
Original filing metadata and source links for verification.
4 source fields
Reporting owner
1 detail
Key filing fact
Rong Zhou filed Form 4 for Amphastar Pharmaceuticals, Inc. (AMPH) on 17 Mar 2026.
Change
- Previous filing in this sequence was filed on 11 Mar 2026.
- Current net transaction value: $0.
Research use
- This tells you what this filing adds before you inspect full transaction and derivative tables.
- You can trace every row back to the original SEC filing document.
Evidence
Filed on Form 4
View source filing
Ownership activity is grounded in SEC Form 4 disclosures.
Reporting Owners (1)
CIK 0001645326
Primary reporting owner
Zhou Rong
- Relationship
- SENIOR EVP, PRODUCTION CENTER
- Address
- C/O AMPHASTAR PHARMACEUTICALS, INC., 11570 6TH STREET, RANCHO CUCAMONGA
- Signature
- /s/ Eva Wen, by power of attorney
- Signature date
- 17 Mar 2026
Reported non-derivative transactions
Shares, units, or other non-derivative securities reported in this filing.
AMPH
transaction
Common Stock
Tax liability
- Transaction value
- Shares
- -1,225
- Change %
- -0.71%
- Price
- $18.18*
- Shares after
- 171,554
- Date
- 15 Mar 2026
- Ownership
- Direct
- Footnotes
- F1
AMPH
holding
Common Stock
No transaction description listed
- Transaction value
- Shares
- Change %
- Price
- Shares after
- 99,668
- Date
- 15 Mar 2026
- Ownership
- See footnote
- Footnotes
- F2
AMPH
holding
Common Stock
No transaction description listed
- Transaction value
- Shares
- Change %
- Price
- Shares after
- 5,000
- Date
- 15 Mar 2026
- Ownership
- See footnote
- Footnotes
- F3
* marks a reported price that did not pass the local price check.
Additional SEC filing notes
Filing notes and footnotes
Explanation of responses 3 footnotes
Footnote F1
The reported shares were withheld to satisfy the reporting person's tax liability in connection with the vesting of restricted stock units, or RSUs.
Footnote F2
The shares are held of record by the Zhou Family Trust for which the reporting person serves as a trustee.
Footnote F3
The shares are held of record by the reporting person's spouse.