STOCK TITAN

Amphastar Pharmaceuticals (AMPH) director receives RSUs and options grant

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

Amphastar Pharmaceuticals director Richard K. Prins reported new equity awards and prior gifting activity. On June 1, 2026 he received 8,143 shares of Common Stock in the form of restricted stock units, all vesting on June 1, 2027, and a stock option for 17,365 shares at an exercise price of $18.42 per share that also vests on June 1, 2027 and expires on June 1, 2036. A previously reported bona fide gift on August 19, 2024 transferred 1,500 shares of Common Stock. Following the latest transactions, he beneficially owned 37,598 shares as of June 1, 2026 after an account reconciliation noted in the filing.

Positive

  • None.

Negative

  • None.
Insider PRINS RICHARD K
Role null
Type Security Shares Price Value
Grant/Award Stock Option (right to buy) 17,365 $0.00 --
Grant/Award Common Stock 8,143 $0.00 --
Gift Common Stock 1,500 $0.00 --
Holdings After Transaction: Stock Option (right to buy) — 17,365 shares (Direct, null); Common Stock — 37,598 shares (Direct, null)
Footnotes (1)
  1. The number of shares beneficially owned following the reported transaction is as of June 1, 2026 and has been reduced by 4,228 shares to reflect a reconciliation to the reporting person's account records. The reported shares are represented by restricted stock units, or RSUs, all of which vest on June 1, 2027. All of the shares subject to the option vest on June 1, 2027.
RSU grant 8,143 shares Restricted stock units vesting on June 1, 2027
Option grant size 17,365 shares Stock option covering Common Stock granted June 1, 2026
Option exercise price $18.42/share Exercise price for 17,365-share stock option
Option expiration June 1, 2036 Expiration date of granted stock option
Gifted shares 1,500 shares Bona fide gift of Common Stock on August 19, 2024
Shares owned after grants 37,598 shares Beneficially owned as of June 1, 2026 after reconciliation
restricted stock units financial
"The reported shares are represented by restricted stock units, or RSUs, all of which vest on June 1, 2027."
Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.
RSUs financial
"The reported shares are represented by restricted stock units, or RSUs, all of which vest on June 1, 2027."
RSUs, or restricted stock units, are a form of company shares given to employees as part of their compensation. They are typically awarded with certain restrictions, such as a waiting period before they can be fully owned or sold, similar to earning a gift that becomes fully yours over time. For investors, RSUs can impact a company's stock offerings and reflect how much the company relies on stock-based incentives to attract and retain talent.
Stock Option (right to buy) financial
"Stock Option (right to buy) with 17,365.0000 shares at a conversion or exercise price of 18.4200."
bona fide gift financial
"The transaction code G is described as a Bona fide gift for 1,500.0000 shares of Common Stock."
A bona fide gift is a genuine, voluntary transfer of money, property, or benefits from one party to another made without expectation of repayment, services, or hidden conditions. Investors care because such gifts can affect company disclosures, related‑party transaction rules, tax treatment, and perceived conflicts of interest; think of it like someone giving you a present with no strings attached — but on a corporate scale, auditors and regulators need to verify it really is unconditional.
beneficially owned financial
"The number of shares beneficially owned following the reported transaction is as of June 1, 2026 and has been reduced by 4,228 shares."
Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.
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SEC Form 4
FORM 4UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number:3235-0287
Estimated average burden
hours per response:0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
PRINS RICHARD K

(Last)(First)(Middle)
C/O AMPHASTAR PHARMACEUTICALS, INC.
11570 6TH STREET

(Street)
RANCHO CUCAMONGA CALIFORNIA 91730

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
Amphastar Pharmaceuticals, Inc. [ AMPH ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
XDirector10% Owner
Officer (give title below)Other (specify below)
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
08/19/2024
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeVAmount(A) or (D)Price
Common Stock08/19/2024G1,500D$029,455(1)D
Common Stock06/01/2026A8,143(2)A$037,598D
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Stock Option (right to buy)$18.4206/01/2026A17,365 (3)06/01/2036Common Stock17,365$017,365D
Explanation of Responses:
1. The number of shares beneficially owned following the reported transaction is as of June 1, 2026 and has been reduced by 4,228 shares to reflect a reconciliation to the reporting person's account records.
2. The reported shares are represented by restricted stock units, or RSUs, all of which vest on June 1, 2027.
3. All of the shares subject to the option vest on June 1, 2027.
/s/ Eva Wen, by power of attorney06/03/2026
** Signature of Reporting PersonDate
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transactions did Amphastar (AMPH) director Richard K. Prins report?

Richard K. Prins reported equity compensation grants and a prior gift. He received 8,143 restricted stock units and a stock option for 17,365 shares, and earlier gifted 1,500 shares. These filings reflect routine director compensation and a bona fide charitable-style transfer.

How many restricted stock units did the Amphastar (AMPH) director receive and when do they vest?

He received 8,143 shares represented by restricted stock units. All these RSUs vest on June 1, 2027, meaning he must remain eligible until that date before the award fully converts into unrestricted Amphastar Common Stock under the reported terms.

What are the terms of the new stock option grant reported for Amphastar (AMPH)?

The director was granted a stock option covering 17,365 shares of Amphastar Common Stock at an exercise price of $18.42 per share. All option shares vest on June 1, 2027 and the option expires on June 1, 2036, providing a long-dated equity incentive.

Did the Amphastar (AMPH) director report any share dispositions in this Form 4?

Yes. The filing shows a bona fide gift of 1,500 shares of Common Stock dated August 19, 2024. A gift disposition transfers shares without consideration and does not represent an open-market sale, so it carries different informational value than typical sell transactions.

What are Richard K. Prins’s Amphastar (AMPH) holdings after these transactions?

After the reported transactions, he beneficially owned 37,598 shares of Amphastar Common Stock as of June 1, 2026. This figure reflects a reconciliation that reduced his prior total by 4,228 shares to align with his account records, according to the filing footnote.

Are the new Amphastar (AMPH) equity awards immediately exercisable or unrestricted?

No. The reported 8,143 restricted stock units and the option for 17,365 shares are subject to vesting. Both the RSUs and all option shares vest on June 1, 2027, so they become fully available only after that vesting date is reached.