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Amphastar Pharmaceuticals, Inc.

AMPH Net selling
CIK 0001297184 #2610 in the set updated 17 Sep 2026
Bought (120 mo)
$663.08K
out of their own pocket, the only kind of buying there is
Sold (120 mo)
$125.69M
$20.49M on a plan · $70.74M straight out of an exercise
Sold at will
$34.46M
151 of 395 sales
Net
−$125.02M
−$33.80M against sales at will

By person

18 insiders · 415 transactions
142×

Jack Yongfeng Zhang holds 142 times base salary in stock. $135.24M of shares against $950.91K in salary for 2025.

Salary from the company's own proxy. The shares are what Jack Yongfeng Zhang last reported holding, valued at $23.63, the price Common Stock was last bought or sold at on the open market here, on 2 Sep 2026.

Insider
Role
Bought
Sold
Net
Holding
Worth
Change
Zhang Jack Y.
CEO & CHIEF SCIENTIFIC OFFICER
$642.82K (2)
$31.38M (35)
−$30.73M
5,723,548
$135.24M
+8.9%
PETERS WILLIAM J
CFO, EVP & TREASURER
—
$23.02M (66) scheduled
−$23.02M
172,846
$4.08M
+130.2%
Luo Mary Z.
COO,Chief Scientist & Chairman
—
$19.97M (14) scheduled
−$19.97M
1,104,416
$26.10M
−24.1%
Shandell Jason B.
President and General Counsel
—
$8.21M (32) scheduled
−$8.21M
179,276
$4.24M
−19.4%
Liawatidewi Yakob
EVP CORP ADMIN CENTER
—
$7.14M (36) scheduled
−$7.14M
126,810
$3.00M
+114.9%
PRINS RICHARD K
Director
—
$6.41M (32) scheduled
−$6.41M
29,625
$700.01K
+36.1%
Zhou Rong
SENIOR EVP, PRODUCTION CENTER
—
$6.29M (33) scheduled
−$6.29M
354,197
$8.37M
+52.0%
ZASLOFF MICHAEL A
Director
—
$5.97M (14) scheduled
−$5.97M
37,667
$890.04K
+16.2%
Lee Howard
Director
—
$4.29M (17) scheduled
−$4.29M
159,350
$3.77M
+39.1%
Petersen Floyd F.
Director
—
$4.29M (79) scheduled
−$4.29M
71,368
$1.69M
+18.3%
Applied Physics & Chemistry Laboratories, Inc. entity
10% owner
—
$2.85M (4)
−$2.85M
7,327,679
$173.15M
−1.8%
Shohet Stephen B.
Director
—
$2.73M (13) scheduled
−$2.73M
30,706
$725.56K
+68.0%
Koo Richard
Director
—
$1.99M (3) scheduled
−$1.99M
269,289
$6.36M
+12.4%
Gerst Diane G.
Director
—
$652.31K (14) scheduled
−$652.31K
31,899
$753.74K
—
Deflin Gayle
Director
—
$494.45K (3)
−$494.45K
19,057
$450.30K
—
Maris David
Director
$20.26K (1)
—
+$20.26K
19,170
$452.97K
+204.3%
Gaugh David Russell
Director
—
—
—
14,447
$341.37K
—
Pierce Anthony T
Director
—
—
—
7,886
$186.34K
—

No percentages here. These insiders hold more than one class of share between them, and the share count on file covers one of them rather than all. Dividing the two would compare different things.

Individual transactions

39
Insider
Date
Role
Action
Shares
Price
Amount
Petersen Floyd F.
3 Nov 2025
Director
Sold on a plan
500
$25.27
$12.63K
Petersen Floyd F.
1 Oct 2025
Director
Sold on a plan
500
$27.20
$13.60K
Petersen Floyd F.
2 Sep 2025
Director
Sold on a plan
500
$30.98
$15.49K
Petersen Floyd F.
1 Aug 2025
Director
Sold on a plan
500
$20.83
$10.42K
Petersen Floyd F.
2 Jul 2025
Director
Sold on a plan
500
$23.47
$11.73K
Petersen Floyd F.
2 Jun 2025
Director
Sold on a plan
500
$25.67
$12.84K
Petersen Floyd F.
1 May 2025
Director
Sold on a plan
500
$24.08
$12.04K
Petersen Floyd F.
1 Apr 2025
Director
Sold on a plan
500
$28.38
$14.19K
Petersen Floyd F.
6 Mar 2025
Director
Sold on a plan
1,000
$27.99
$27.99K
PETERS WILLIAM J
27 Jun 2024
CFO, EVP & TREASURER
Sold on a plan
635
$41.29
$26.22K
PETERS WILLIAM J
27 Jun 2024
CFO, EVP & TREASURER
Sold on a plan
2,961
$40.85
$120.95K
Petersen Floyd F.
3 Jun 2024
Director
Sold on a plan
500
$42.65
$21.33K
Petersen Floyd F.
1 May 2024
Director
Sold on a plan
500
$41.67
$20.84K
Petersen Floyd F.
1 Apr 2024
Director
Sold on a plan
500
$43.43
$21.71K
Petersen Floyd F.
1 Mar 2024
Director
Sold on a plan
49
$46.53
$2.28K
Petersen Floyd F.
1 Mar 2024
Director
Sold on a plan
451
$45.60
$20.57K
Petersen Floyd F.
1 Feb 2024
Director
Sold on a plan
26
$53.64
$1.39K
Petersen Floyd F.
1 Feb 2024
Director
Sold on a plan
474
$53.07
$25.15K
Luo Mary Z.
10 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
1,716
$57.00
$97.82K
Luo Mary Z.
10 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
920
$55.95
$51.48K
Luo Mary Z.
10 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
50,514
$54.89
$2.77M
Luo Mary Z.
10 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
78,236
$54.32
$4.25M
Luo Mary Z.
9 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
3,714
$58.35
$216.72K
Luo Mary Z.
9 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
31,764
$57.70
$1.83M
Luo Mary Z.
9 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
50,678
$56.70
$2.87M
Luo Mary Z.
8 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
2,152
$63.27
$136.15K
Luo Mary Z.
8 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
1,663
$61.81
$102.78K
Luo Mary Z.
8 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
4,261
$61.19
$260.74K
Luo Mary Z.
8 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
27,563
$59.99
$1.65M
Luo Mary Z.
8 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
37,865
$59.24
$2.24M
Luo Mary Z.
8 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
41,282
$58.25
$2.40M
Luo Mary Z.
8 Jan 2024
COO,Chief Scientist & Chairman
Sold on a plan
18,858
$56.98
$1.07M
Petersen Floyd F.
2 Jan 2024
Director
Sold on a plan
353
$61.70
$21.78K
Petersen Floyd F.
2 Jan 2024
Director
Sold on a plan
147
$60.56
$8.90K
Petersen Floyd F.
1 Dec 2023
Director
Sold on a plan
365
$58.15
$21.22K
Petersen Floyd F.
1 Dec 2023
Director
Sold on a plan
135
$57.24
$7.73K
Petersen Floyd F.
1 Nov 2023
Director
Sold on a plan
500
$45.30
$22.65K
Petersen Floyd F.
2 Oct 2023
Director
Sold on a plan
500
$45.78
$22.89K
Petersen Floyd F.
3 Apr 2023
Director
Sold on a plan
491
$37.72
$18.52K
Showing 250 of 415 transactions. The figures above use every one of them.

What was left out

Form 4 filings counted 484
Amendments (4/A) skipped 1
Filings about a different issuer 0
Unreadable filings 0
Joint filings 50
Sales on a Rule 10b5-1 plan 39
Sales straight out of an exercise 205
Sales at will 151
Transactions with no price 0
Shares from compensation/vesting 15,900,120
Sales filed before the plan box existed 133
History held since 2 Sep 2016