Amphastar Pharmaceuticals, Inc.

AMPHNASDAQHealthcare● Active

$19.49

$-0.26(-1.29%)

Market Cap$859150527

P/E Ratio—

52W High$31.26

52W Low$16.65

Avg Volume610K

Open$19.75

Beta0.90

Overview

Amphastar Pharmaceuticals, Inc. (AMPH) Insider Trading

Form 4 buy vs sell counts, ratio, and sentiment — switch this quarter or last 12 months; chart and transactions below.

SEC EDGAR · FMP · AMPH · as of Jun 8, 2026

Activity summary

Buy transactions

P-Purchase only

Sell transactions

12 Months

Buy/Sell ratio

0.00

Buy/Sell (by trades)

Overall sentiment

BEARISH

↑ Buy 0%Active transactions only · RSU vesting excluded100% Sell ↓

Amphastar Pharmaceuticals, Inc. insiders have been primarily selling shares over the past 12 Months. Selling activity is often driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment toward the company.

▸ Source: SEC EDGAR · Form 3 & 4 · via Financial Modeling Prep · Buy = P-Purchase only · Sell = S-Sale only

As of Jun 8, 2026

AMPH insider buying and selling by quarter

AMPH insider selling · AMPH insider buying stocks · quarterly insider activity

Total insider buying (incl. awards)Total insider selling

1.3M641K0

2024 Q3

2024 Q4

2025 Q1

2025 Q2

2025 Q3

2025 Q4

2026 Q1

2026 Q2

Mobile shows last 4Q · Desktop shows full 8Q

▸ Source: SEC EDGAR · Form 3 & 4 · via Financial Modeling Prep · last 8 quarters

As of Jun 8, 2026

Active insiders

Most active in past 12 months · AMPH ceo insider trading

Showing all insiders · Click a card to filter the transactions table below

▸ Aggregated from reportingName · top 5 by trade count (12M) · no extra API

Recent insider transactions

AMPH executive sell shares · AMPH board member insider trading · AMPH insider trading SEC filing

Showing 73 most recent · Common Stock · Form 4 only

Scroll horizontally to see all columns

Date	Insider	Type	Shares	Price	Value	After trans.	Filing
Jun 1, 2026	PRINS RICHARD K Director	Award	8,143	—	—	37,598	Form 4
Aug 19, 2024	PRINS RICHARD K Director	Gift	1,500	—	—	29,455	Form 4
Jun 1, 2026	Lee Howard Director	Award	8,143	—	—	160,119	Form 4
Jun 2, 2026	Lee Howard Director	Other	769	$18.45	$14K	159,350	Form 4
Jun 1, 2026	ZASLOFF MICHAEL A Director	Award	8,143	—	—	37,667	Form 4
Jun 1, 2026	ZASLOFF MICHAEL A Director	Award	17,365	$18.42	$320K	17,365	Form 4
Jun 1, 2026	Gerst Diane G. Director	Award	8,143	—	—	31,899	Form 4
Jun 1, 2026	Gaugh David Russell Director	Award	8,143	—	—	14,447	Form 4
Jun 1, 2026	Deflin Gayle Director	Award	8,143	—	—	19,057	Form 4
Mar 15, 2026	Liawatidewi Yakob EVP CORP ADMIN CENTER · Director	Other	1,033	$18.18	$19K	121,892	Form 4
Mar 15, 2026	Zhou Rong SENIOR EVP, PRODUCTION CENTER	Other	1,225	$18.18	$22K	171,554	Form 4
Mar 15, 2026	PETERS WILLIAM J CFO, EVP & TREASURER · Director	Other	1,973	$18.18	$36K	175,063	Form 4
Mar 15, 2026	Zhang Jack Y. CEO & CHIEF SCIENTIFIC OFFICER · Director	Other	9,784	$18.18	$178K	2,990,052	Form 4
Mar 15, 2026	Zhang Jack Y. CEO & CHIEF SCIENTIFIC OFFICER · Director	Other	2,908	$18.18	$53K	1,245,125	Form 4
Mar 9, 2026	PETERS WILLIAM J CFO, EVP & TREASURER · Director	Award	58,693	—	—	180,333	Form 4
Mar 10, 2026	PETERS WILLIAM J CFO, EVP & TREASURER · Director	Other	3,297	$18.91	$62K	177,036	Form 4
Mar 10, 2026	Zhou Rong SENIOR EVP, PRODUCTION CENTER	Other	2,215	$18.91	$42K	172,779	Form 4
Mar 9, 2026	Liawatidewi Yakob EVP CORP ADMIN CENTER · Director	Award	35,450	—	—	124,795	Form 4
Mar 10, 2026	Liawatidewi Yakob EVP CORP ADMIN CENTER · Director	Other	1,870	$18.91	$35K	122,925	Form 4
Mar 9, 2026	Zhang Jack Y. CEO & CHIEF SCIENTIFIC OFFICER · Director	Award	180,504	—	—	3,014,621	Form 4
Mar 10, 2026	Zhang Jack Y. CEO & CHIEF SCIENTIFIC OFFICER · Director	Other	14,785	$18.91	$280K	2,999,836	Form 4
Mar 9, 2026	Zhang Jack Y. CEO & CHIEF SCIENTIFIC OFFICER · Director	Award	72,462	—	—	1,252,428	Form 4
Mar 10, 2026	Zhang Jack Y. CEO & CHIEF SCIENTIFIC OFFICER · Director	Other	4,395	$18.91	$83K	1,248,033	Form 4
Mar 6, 2026	PETERS WILLIAM J CFO, EVP & TREASURER · Director	Other	2,146	$19.34	$42K	121,640	Form 4
Mar 6, 2026	Zhou Rong SENIOR EVP, PRODUCTION CENTER	Other	1,357	$19.34	$26K	135,562	Form 4

PRINS RICHARD K

Director

Award

Date

Jun 1

8,143

Price

—

Value

—

View Form 4 on SEC.gov

PRINS RICHARD K

Director

Gift

Date

Aug 19

1,500

Price

—

Value

—

View Form 4 on SEC.gov

Lee Howard

Director

Award

Date

Jun 1

8,143

Price

—

Value

—

View Form 4 on SEC.gov

Lee Howard

Director

Other

Date

Jun 2

769

Price

$18.45

Value

$14K

View Form 4 on SEC.gov

ZASLOFF MICHAEL A

Director

Award

Date

Jun 1

8,143

Price

—

Value

—

View Form 4 on SEC.gov

ZASLOFF MICHAEL A

Director

Award

Date

Jun 1

17,365

Price

$18.42

Value

$320K

View Form 4 on SEC.gov

Gerst Diane G.

Director

Award

Date

Jun 1

8,143

Price

—

Value

—

View Form 4 on SEC.gov

Gaugh David Russell

Director

Award

Date

Jun 1

8,143

Price

—

Value

—

View Form 4 on SEC.gov

Deflin Gayle

Director

Award

Date

Jun 1

8,143

Price

—

Value

—

View Form 4 on SEC.gov

Liawatidewi Yakob

EVP CORP ADMIN CENTER · Director

Other

Date

Mar 15

1,033

Price

$18.18

Value

$19K

View Form 4 on SEC.gov

Zhou Rong

SENIOR EVP, PRODUCTION CENTER

Other

Date

Mar 15

1,225

Price

$18.18

Value

$22K

View Form 4 on SEC.gov

PETERS WILLIAM J

CFO, EVP & TREASURER · Director

Other

Date

Mar 15

1,973

Price

$18.18

Value

$36K

View Form 4 on SEC.gov

Zhang Jack Y.

CEO & CHIEF SCIENTIFIC OFFICER · Director

Other

Date

Mar 15

9,784

Price

$18.18

Value

$178K

View Form 4 on SEC.gov

Zhang Jack Y.

CEO & CHIEF SCIENTIFIC OFFICER · Director

Other

Date

Mar 15

2,908

Price

$18.18

Value

$53K

View Form 4 on SEC.gov

PETERS WILLIAM J

CFO, EVP & TREASURER · Director

Award

Date

Mar 9

58,693

Price

—

Value

—

View Form 4 on SEC.gov

PETERS WILLIAM J

CFO, EVP & TREASURER · Director

Other

Date

Mar 10

3,297

Price

$18.91

Value

$62K

View Form 4 on SEC.gov

Zhou Rong

SENIOR EVP, PRODUCTION CENTER

Other

Date

Mar 10

2,215

Price

$18.91

Value

$42K

View Form 4 on SEC.gov

Liawatidewi Yakob

EVP CORP ADMIN CENTER · Director

Award

Date

Mar 9

35,450

Price

—

Value

—

View Form 4 on SEC.gov

Liawatidewi Yakob

EVP CORP ADMIN CENTER · Director

Other

Date

Mar 10

1,870

Price

$18.91

Value

$35K

View Form 4 on SEC.gov

Zhang Jack Y.

CEO & CHIEF SCIENTIFIC OFFICER · Director

Award

Date

Mar 9

180,504

Price

—

Value

—

View Form 4 on SEC.gov

Zhang Jack Y.

CEO & CHIEF SCIENTIFIC OFFICER · Director

Other

Date

Mar 10

14,785

Price

$18.91

Value

$280K

View Form 4 on SEC.gov

Zhang Jack Y.

CEO & CHIEF SCIENTIFIC OFFICER · Director

Award

Date

Mar 9

72,462

Price

—

Value

—

View Form 4 on SEC.gov

Zhang Jack Y.

CEO & CHIEF SCIENTIFIC OFFICER · Director

Other

Date

Mar 10

4,395

Price

$18.91

Value

$83K

View Form 4 on SEC.gov

PETERS WILLIAM J

CFO, EVP & TREASURER · Director

Other

Date

Mar 6

2,146

Price

$19.34

Value

$42K

View Form 4 on SEC.gov

Zhou Rong

SENIOR EVP, PRODUCTION CENTER

Other

Date

Mar 6

1,357

Price

$19.34

Value

$26K

View Form 4 on SEC.gov

⚡ = value ≥ $1M · Award/Option price shows — · formType=4 · securityName=Common Stock · url → sec.gov/Archives/edgar

1 / 3

▸ Source: SEC EDGAR · Form 4 filings · ⚡ = value ≥ $1M · Award/Option price shows —

About AMPH insider trading

AMPH insider trades

Amphastar Pharmaceuticals, Inc. (AMPH) insider trading data is sourced from SEC Form 4 filings submitted by corporate insiders, including Zhang Jack Y. (CEO & CHIEF SCIENTIFIC OFFICER · Director), Petersen Floyd F. (Director), Zhou Rong (SENIOR EVP, PRODUCTION CENTER). Over the past 12 months, 5 insiders have filed transactions with the SEC. AMPH insiders have been primarily selling, which may reflect pre-scheduled Rule 10b5-1 plan executions.

For Amphastar Pharmaceuticals, Inc.'s institutional ownership breakdown and insider ownership percentage, see the Ownership tab → Ownership tab →

Buy/Sell signal logic

acquisitionOrDisposition field:

A = Acquisition (buy) · D = Disposition (sell)

RSU vesting (M-Exempt) excluded from sentiment

Form 4SEC filing required within 2 business days of any insider transaction

10b5-1Pre-scheduled trading plan that allows insiders to sell on autopilot

Open MktDirect purchase or sale on the open market (excludes awards, options)

Ownership SEC filings Financial statements Price history Forecast & ratings Earnings

Frequently asked questions

AMPH insider trading · 5 questions

The insiders of Amphastar Pharmaceuticals, Inc. (AMPH) include executives and directors such as Zhang Jack Y. (CEO & CHIEF SCIENTIFIC OFFICER · Director), Petersen Floyd F. (Director), Zhou Rong (SENIOR EVP, PRODUCTION CENTER), among others. Over the past 12 months, 5 insiders have filed Form 4 transactions with the SEC. Insider transactions are required to be reported within 2 business days of the trade date.

AMPH board member insider tradingwho are AMPH insidersAMPH insider rosterAmphastar Pharmaceuticals, Inc. executives insider activity

▸ Source: FMP /stable/insider-trading/search · SEC EDGAR Form 3 & 4 · acquisitionOrDisposition A=Buy, D=Sell · RSU vesting (M-Exempt) excluded from sentiment bar · As of Jun 8, 2026