Amphastar Pharmaceuticals Ownership

Who are the major shareholders and have insiders been buying or selling?

Recent Insider Transactions

NasdaqGS:AMPH Recent Insider Transactions by Companies or Individuals
Date	Value	Name	Entity	Role	Shares	Max Price
12 Dec 25	SellUS$107,508	Floyd Petersen	Individual		4,163	US$25.92

Insider Trading Volume

Insider Buying: AMPH insiders have only sold shares in the past 3 months.

Ownership Breakdown

What is the ownership structure of AMPH?
Owner Type	Number of Shares	Ownership Percentage
State or Government	9,300	0.0202%
General Public	1,752,732	3.81%
Individual Insiders	4,311,528	9.38%
Private Companies	6,827,679	14.9%
Institutions	33,050,935	71.9%

Dilution of Shares: Shareholders have not been meaningfully diluted in the past year.

Top Shareholders

Top 25 shareholders own 75.34% of the company

Ownership	Name	Shares	Current Value	Change %	Portfolio %
14.9%	Applied Physics & Chemistry Laboratories, Inc.	6,827,679	US$188.6m	0%	no data
11.9%	BlackRock, Inc.	5,485,006	US$151.5m	-3.24%	no data
5.73%	The Vanguard Group, Inc.	2,631,040	US$72.7m	-2.08%	no data
5.71%	Yongfeng Zhang	2,623,280	US$72.5m	0%	no data
4.2%	TD Asset Management, Inc.	1,931,892	US$53.4m	-5.06%	0.03%
3.82%	Dimensional Fund Advisors LP	1,755,665	US$48.5m	7.92%	0.01%
3.27%	State Street Global Advisors, Inc.	1,500,742	US$41.5m	-4.79%	no data
2.95%	Fuller & Thaler Asset Management, Inc.	1,353,927	US$37.4m	7.13%	0.12%
2.55%	Boston Trust Walden Company	1,173,107	US$32.4m	-0.28%	0.22%
2.47%	The Toronto-Dominion Bank	1,133,986	US$31.3m	-7.6%	0.03%
2.37%	Ziping Luo	1,090,893	US$30.1m	0%	no data
2.01%	Geode Capital Management, LLC	922,577	US$25.5m	-5.21%	no data
1.9%	Marshall Wace LLP	874,068	US$24.1m	2.99%	0.03%
1.52%	Millennium Management LLC	697,765	US$19.3m	12.7%	0.01%
1.28%	Renaissance Technologies LLC	586,900	US$16.2m	1.8%	0.02%
1.13%	D. E. Shaw & Co., L.P.	517,222	US$14.3m	76%	0.01%
1.01%	Bridgeway Capital Management, LLC	462,132	US$12.8m	171%	0.18%
0.92%	Systematic Financial Management LP	423,112	US$11.7m	17.8%	0.24%
0.87%	Northern Trust Global Investments	399,470	US$11.0m	-5.14%	no data
0.86%	Algert Global LLC	392,902	US$10.9m	216%	0.17%
0.85%	Arrowstreet Capital, Limited Partnership	392,310	US$10.8m	383%	0.01%
0.8%	UBS Asset Management AG	366,609	US$10.1m	128%	no data
0.8%	Royce & Associates, LP	366,322	US$10.1m	29.4%	0.09%
0.78%	Charles Schwab Investment Management, Inc.	356,409	US$9.8m	2.78%	no data
0.77%	Invesco Capital Management LLC	354,585	US$9.8m	-1.86%	no data

Company Analysis and Financial Data Status

Data	Last Updated (UTC time)
Company Analysis	2026/01/07 15:53
End of Day Share Price	2026/01/07 00:00
Earnings	2025/09/30
Annual Earnings	2024/12/31

Data Sources

The data used in our company analysis is from S&P Global Market Intelligence LLC. The following data is used in our analysis model to generate this report. Data is normalised which can introduce a delay from the source being available.

Package	Data	Timeframe	Example US Source ^*
Company Financials	10 years	Income statement Cash flow statement Balance sheet	SEC Form 10-K SEC Form 10-Q
Analyst Consensus Estimates	+3 years	Forecast financials Analyst price targets	Analyst Research Reports Blue Matrix
Market Prices	30 years	Stock prices Dividends, Splits and Actions	ICE Market Data SEC Form S-1
Ownership	10 years	Top shareholders Insider trading	SEC Form 4 SEC Form 13D
Management	10 years	Leadership team Board of directors	SEC Form 10-K SEC Form DEF 14A
Key Developments	10 years	Company announcements	SEC Form 8-K

^* Example for US securities, for non-US equivalent regulatory forms and sources are used.

Unless specified all financial data is based on a yearly period but updated quarterly. This is known as Trailing Twelve Month (TTM) or Last Twelve Month (LTM) Data. Learn more.

Analysis Model and Snowflake

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Learn about the world class team who designed and built the Simply Wall St analysis model.

Industry and Sector Metrics

Our industry and section metrics are calculated every 6 hours by Simply Wall St, details of our process are available on Github.

Analyst Sources

Amphastar Pharmaceuticals, Inc. is covered by 15 analysts. 6 of those analysts submitted the estimates of revenue or earnings used as inputs to our report. Analysts submissions are updated throughout the day.

Analyst	Institution
Glen Santangelo	Barclays
Gary Nachman	BMO Capital Markets Equity Research
Jason Matthew Gerberry	BofA Global Research