Company Analysis

Amphastar Pharmaceuticals, Inc. (AMPH)

Nasdaq: AMPH · Pharmaceutical Preparations · Rancho Cucamonga, CA · filing with the SEC since 2005
Grade6.5
◀ Past 7.8● Present 7.4▶ Future 4.1

Who owns Amphastar Pharmaceuticals, Inc.

As filed with the SEC
Holders of 5% or more
3
Jack Y. Zhang holds 24.8% of Common Stock, as its SCHEDULE 13G/A filed Feb 7, 2025 says.
Directors and officers
13
report now, of 17 people on the record since 2014. Their holdings as a group are not read here.
Institutions as a whole
n/a
The record does not read the share held by managers that file Form 13F, so none is printed and no split of the rest is estimated. What it holds is the 3 named at left.
Holders of 5% or moreshare of the class, as filed
Jack Y. Zhang
24.8%
Blackrock, Inc.
11.5%
Dimensional Fund Advisors LP
5.2%
The Vanguard Group
SCHEDULE 13G/A · filed Mar 26, 2026 · Common Stock · reported falling below 5%
under 5%
What AMPH reports owning in othersstakes of 5% or more, and other ties
Other ties the annual report names
Anp
An entity · legal entity · owns, named in the 10-K filed Feb 26, 2026

7 subsidiaries in 4 countries, from the list filed with the 10-K filed Feb 26, 2026.

Insider tradesForm 4
12sales
0purchases
4sales on a scheduled plan
4people selling
$2.5Msold, in dollars
$0bought, in dollars
Open-market trades on Form 4 from Nov 6, 2025 to Nov 6, 2026. A scheduled plan is a selling program set in advance under SEC rule 10b5-1. The trades are listed as filed and do not feed the grade.
By calendar yearSoldBought
17181920212223242526
2026 runs to Nov 6, 2026. Dollars as filed, summed by the transaction date.
People who traded in the window4 of 18 on the roster
PersonRole as filedSalesSoldOn a planBuysBought
Peters William JCFO, EVP & TREASURER4$1.1M40$0
Zhou RongSENIOR EVP, PRODUCTION CENTER3$600,00000$0
Petersen Floyd F.director3$500,00000$0
Prins Richard Kdirector2$300,00000$0
SI Assistanton AMPH · research, not advice