Key facts
- This page summarizes Howard Lee's Form 4 filing for Amphastar Pharmaceuticals, Inc. (AMPH).
- 3 reported transactions and 1 derivative row are listed below.
- Accepted by SEC: 03 Jun 2026, 21:20.
Howard Lee - 01 Jun 2026 Form 4 Insider Report for Amphastar Pharmaceuticals, Inc. (AMPH)
- Reporting relationship
- Director
- Issuer ticker
- AMPH
- Reported as of
- 01 Jun 2026
- Net transaction value
- $0
- SEC form
- 4
- Accepted by SEC
- 03 Jun 2026, 21:20:03 UTC
- Prior SEC filing
- 04 Jun 2025
- 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
Howard Lee filed Form 4 for Amphastar Pharmaceuticals, Inc. (AMPH) on 03 Jun 2026.
Change
- Previous filing in this sequence was filed on 04 Jun 2025.
- 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 0001379941
Primary reporting owner
Lee Howard
- Relationship
- Director
- Address
- C/O AMPHASTAR PHARMACEUTICALS, INC., 11570 6TH STREET, RANCHO CUCAMONGA
- Signature
- /s/ Eva Wen, by power of attorney
- Signature date
- 03 Jun 2026
Reported non-derivative transactions
Shares, units, or other non-derivative securities reported in this filing.
AMPH
transaction
Common Stock
Award
- Transaction value
- Shares
- +8,143
- Change %
- +5.4%
- Price
- $0.000000*
- Shares after
- 160,119
- Date
- 01 Jun 2026
- Ownership
- Direct
- Footnotes
- F1
AMPH
transaction
Common Stock
Tax liability
- Transaction value
- Shares
- -769
- Change %
- -0.48%
- Price
- $18.45*
- Shares after
- 159,350
- Date
- 02 Jun 2026
- Ownership
- Direct
- Footnotes
- F2
Reported derivative securities
Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.
AMPH
transaction
Derivative
Stock Option (right to buy)
Award
- Transaction value
- Shares
- +17,365
- Change %
- Price
- $0.000000*
- Shares after
- 17,365
- Date
- 01 Jun 2026
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 17,365
- Exercise price
- $18.42
- 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 are represented by restricted stock units, or RSUs, all of which vest on June 1, 2027.
Footnote F2
The reported shares were withheld to satisfy the reporting person's tax liability in connection with the vesting of RSUs.
Footnote F3
All of the shares subject to the option vest on June 1, 2027.