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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

121
Insider
Date
Role
Action
Shares
Price
Amount
PETERS WILLIAM J
7 Aug 2026
CFO, EVP & TREASURER
Sold after exercise
8,180
$22.48
$183.89K
Zhou Rong
17 Dec 2025
SENIOR EVP, PRODUCTION CENTER
Sold after exercise
9,787
$26.20
$256.38K
PRINS RICHARD K
25 Nov 2025
Director
Sold after exercise
4,179
$27.10
$113.25K
Petersen Floyd F.
13 Nov 2025
Director
Sold after exercise
16,679
$26.49
$441.84K
PETERS WILLIAM J
4 Mar 2025
CFO, EVP & TREASURER
Sold after exercise
4,231
$27.54
$116.52K
Zhou Rong
13 Dec 2024
SENIOR EVP, PRODUCTION CENTER
Sold after exercise
8,000
$45.23
$361.84K
Zhou Rong
12 Dec 2024
SENIOR EVP, PRODUCTION CENTER
Sold after exercise
7,000
$44.43
$310.98K
PRINS RICHARD K
9 Dec 2024
Director
Sold after exercise
10,000
$43.77
$437.70K
PRINS RICHARD K
12 Nov 2024
Director
Sold after exercise
5,000
$48.80
$243.99K
Zhou Rong
12 Nov 2024
SENIOR EVP, PRODUCTION CENTER
Sold after exercise
6,893
$48.88
$336.93K
PETERS WILLIAM J
6 Nov 2024
CFO, EVP & TREASURER
Sold after exercise
7,426
$52.05
$386.52K
Liawatidewi Yakob
6 Nov 2024
EVP CORP ADMIN CENTER
Sold after exercise
5,214
$52.05
$271.39K
Zhou Rong
13 Sep 2024
SENIOR EVP, PRODUCTION CENTER
Sold after exercise
3,000
$48.26
$144.78K
Zhou Rong
26 Aug 2024
SENIOR EVP, PRODUCTION CENTER
Sold after exercise
4,000
$48.35
$193.40K
PRINS RICHARD K
12 Aug 2024
Director
Sold after exercise
17,101
$43.07
$736.55K
PETERS WILLIAM J
31 Jul 2024
CFO, EVP & TREASURER
Sold after exercise
10,282
$44.23
$454.77K
PETERS WILLIAM J
6 Mar 2024
CFO, EVP & TREASURER
Sold after exercise
51
$48.00
$2.45K
PETERS WILLIAM J
6 Mar 2024
CFO, EVP & TREASURER
Sold after exercise
4,681
$46.98
$219.90K
PETERS WILLIAM J
6 Mar 2024
CFO, EVP & TREASURER
Sold after exercise
13,404
$46.30
$620.54K
Zhou Rong
4 Dec 2023
Senior EVP, Production Center
Sold after exercise
3,514
$59.58
$209.36K
Zhou Rong
1 Dec 2023
Senior EVP, Production Center
Sold after exercise
4,316
$58.58
$252.83K
PETERS WILLIAM J
14 Nov 2023
CFO, EVP & Treasurer
Sold after exercise
14,868
$56.53
$840.55K
PETERS WILLIAM J
14 Nov 2023
CFO, EVP & Treasurer
Sold after exercise
30,162
$55.67
$1.68M
PETERS WILLIAM J
14 Nov 2023
CFO, EVP & Treasurer
Sold after exercise
14,220
$54.76
$778.72K
PETERS WILLIAM J
6 Sep 2023
CFO, EVP & Treasurer
Sold after exercise
59
$52.26
$3.08K
PETERS WILLIAM J
6 Sep 2023
CFO, EVP & Treasurer
Sold after exercise
60,684
$51.75
$3.14M
Liawatidewi Yakob
28 Aug 2023
EVP Corp Admin Center
Sold after exercise
28,816
$53.13
$1.53M
PETERS WILLIAM J
15 Jun 2023
CFO, EVP & Treasurer
Sold after exercise
13,000
$52.79
$686.27K
PETERS WILLIAM J
15 Jun 2023
CFO, EVP & Treasurer
Sold after exercise
12,000
$50.79
$609.48K
PETERS WILLIAM J
15 Jun 2023
CFO, EVP & Treasurer
Sold after exercise
11,868
$48.79
$579.04K
Zhou Rong
15 Jun 2023
EVP, Production Center
Sold after exercise
5,000
$51.79
$258.95K
Zhou Rong
13 Jun 2023
EVP, Production Center
Sold after exercise
5,000
$48.24
$241.20K
PETERS WILLIAM J
2 Jun 2023
CFO, EVP & Treasurer
Sold after exercise
11,000
$46.35
$509.86K
Lee Howard
1 Jun 2023
Director
Sold after exercise
16,679
$45.02
$750.96K
Zhou Rong
18 May 2023
EVP, Production Center
Sold after exercise
10,000
$44.21
$442.05K
PETERS WILLIAM J
18 May 2023
CFO, EVP & Treasurer
Sold after exercise
10,500
$44.35
$465.68K
PRINS RICHARD K
15 May 2023
Director
Sold after exercise
5,000
$43.50
$217.50K
PRINS RICHARD K
12 May 2023
Director
Sold after exercise
5,000
$42.06
$210.32K
PETERS WILLIAM J
17 Apr 2023
CFO, EVP & Treasurer
Sold after exercise
5,632
$42.35
$238.52K
PETERS WILLIAM J
13 Apr 2023
CFO, EVP & Treasurer
Sold after exercise
4,868
$42.35
$206.16K
Liawatidewi Yakob
13 Apr 2023
EVP Corp Admin Center
Sold after exercise
6,494
$42.00
$272.75K
Liawatidewi Yakob
13 Apr 2023
EVP Corp Admin Center
Sold after exercise
5,000
$41.00
$205.00K
PETERS WILLIAM J
10 Apr 2023
CFO, EVP & Treasurer
Sold after exercise
10,032
$40.35
$404.79K
Liawatidewi Yakob
10 Apr 2023
EVP Corp Admin Center
Sold after exercise
5,000
$40.00
$200.00K
PETERS WILLIAM J
15 Mar 2023
CFO, EVP & Treasurer
Sold after exercise
12,776
$36.43
$465.47K
PETERS WILLIAM J
1 Mar 2023
CFO, EVP & Treasurer
Sold after exercise
10,974
$36.33
$398.69K
Liawatidewi Yakob
9 Aug 2022
EVP Corp Admin Center
Sold after exercise
3,055
$39.00
$119.15K
PETERS WILLIAM J
9 Aug 2022
CFO, EVP & Treasurer
Sold after exercise
10,000
$38.35
$383.50K
Liawatidewi Yakob
8 Aug 2022
EVP Corp Admin Center
Sold after exercise
5,000
$38.00
$190.00K
Gerst Diane G.
18 Jul 2022
Director
Sold after exercise
1,520
$37.23
$56.60K
Liawatidewi Yakob
15 Jul 2022
EVP Corp Admin Center
Sold after exercise
7,359
$36.97
$272.09K
Liawatidewi Yakob
15 Jul 2022
EVP Corp Admin Center
Sold after exercise
3,478
$35.94
$125.00K
Gerst Diane G.
11 Jul 2022
Director
Sold after exercise
1,521
$36.26
$55.14K
Gerst Diane G.
5 Jul 2022
Director
Sold after exercise
1,813
$35.00
$63.46K
PETERS WILLIAM J
30 Jun 2022
CFO, EVP & Treasurer
Sold after exercise
18,386
$34.95
$642.59K
Gerst Diane G.
30 Jun 2022
Director
Sold after exercise
5,146
$35.00
$180.11K
Lee Howard
6 Jun 2022
Director
Sold after exercise
10,291
$37.79
$388.86K
Lee Howard
23 May 2022
Director
Sold after exercise
10,000
$34.93
$349.32K
Petersen Floyd F.
18 May 2022
Director
Sold after exercise
9,924
$35.05
$347.83K
ZASLOFF MICHAEL A
16 May 2022
Director
Sold after exercise
10,291
$35.61
$366.50K
ZASLOFF MICHAEL A
16 Mar 2022
Director
Sold after exercise
10,000
$33.71
$337.07K
PETERS WILLIAM J
16 Mar 2022
CFO, EVP & Treasurer
Sold after exercise
3,760
$34.36
$129.20K
PETERS WILLIAM J
16 Mar 2022
CFO, EVP & Treasurer
Sold after exercise
47,017
$33.93
$1.60M
PRINS RICHARD K
15 Mar 2022
Director
Sold after exercise
10,000
$34.02
$340.21K
PETERS WILLIAM J
7 Mar 2022
CFO, EVP & Treasurer
Sold after exercise
13,026
$29.35
$382.31K
PETERS WILLIAM J
25 Feb 2022
CFO, EVP & Treasurer
Sold after exercise
12,000
$28.95
$347.40K
PETERS WILLIAM J
25 Feb 2022
CFO, EVP & Treasurer
Sold after exercise
11,000
$27.95
$307.45K
Zhou Rong
25 Feb 2022
EVP, Production Center
Sold after exercise
13,246
$28.77
$381.09K
PETERS WILLIAM J
8 Feb 2022
CFO, EVP & Treasurer
Sold after exercise
10,000
$26.95
$269.50K
Zhou Rong
8 Feb 2022
EVP, Production Center
Sold after exercise
7,000
$26.77
$187.39K
PETERS WILLIAM J
10 Jan 2022
CFO, EVP & Treasurer
Sold after exercise
16,000
$25.40
$406.40K
Zhou Rong
10 Jan 2022
EVP, Production Center
Sold after exercise
10,251
$25.77
$264.16K
Zhou Rong
10 Jan 2022
EVP, Production Center
Sold after exercise
10,677
$24.96
$266.53K
PETERS WILLIAM J
7 Jan 2022
CFO, EVP & Treasurer
Sold after exercise
11,776
$24.90
$293.22K
PETERS WILLIAM J
7 Jan 2022
CFO, EVP & Treasurer
Sold after exercise
20,000
$24.15
$483.00K
PETERS WILLIAM J
30 Dec 2021
CFO, EVP & Treasurer
Sold after exercise
10,000
$23.40
$234.00K
PETERS WILLIAM J
21 Dec 2021
CFO, EVP & Treasurer
Sold after exercise
8,256
$22.40
$184.93K
PETERS WILLIAM J
16 Dec 2021
CFO, EVP & Treasurer
Sold after exercise
1,744
$22.40
$39.07K
PRINS RICHARD K
10 Dec 2021
Director
Sold after exercise
5,291
$21.36
$113.01K
PRINS RICHARD K
22 Nov 2021
Director
Sold after exercise
5,000
$21.22
$106.10K
PETERS WILLIAM J
11 Nov 2021
CFO, EVP & Treasurer
Sold after exercise
10,000
$21.33
$213.30K
Zhou Rong
11 Nov 2021
EVP, Production Center
Sold after exercise
7,813
$21.67
$169.31K
Liawatidewi Yakob
2 Aug 2021
EVP Corp Admin Center
Sold after exercise
8,932
$21.14
$188.80K
Zhou Rong
2 Aug 2021
EVP, Production Center
Sold after exercise
9,123
$21.24
$193.73K
Zhou Rong
26 Jul 2021
EVP, Production Center
Sold after exercise
6,000
$20.87
$125.22K
Zhou Rong
20 Jul 2021
EVP, Production Center
Sold after exercise
5,187
$20.57
$106.70K
Liawatidewi Yakob
15 Jul 2021
EVP Corp Admin Center
Sold after exercise
31,524
$20.01
$630.69K
PETERS WILLIAM J
7 Jul 2021
CFO, EVP & Treasurer
Sold after exercise
10,000
$20.37
$203.74K
Lee Howard
8 Jun 2021
Director
Sold after exercise
8,000
$19.31
$154.51K
Zhou Rong
8 Jun 2021
EVP, Production Center
Sold after exercise
8,180
$19.34
$158.18K
Lee Howard
7 Jun 2021
Director
Sold after exercise
7,827
$19.28
$150.94K
Petersen Floyd F.
7 Jun 2021
Director
Sold after exercise
15,827
$19.34
$306.04K
PRINS RICHARD K
7 Jun 2021
Director
Sold after exercise
5,000
$18.70
$93.50K
PRINS RICHARD K
4 Jun 2021
Director
Sold after exercise
5,000
$18.77
$93.85K
Petersen Floyd F.
3 Jun 2021
Director
Sold after exercise
10,000
$18.65
$186.53K
Koo Richard
1 Jun 2021
Director
Sold after exercise
25,827
$19.28
$498.01K
Lee Howard
20 May 2021
Director
Sold after exercise
10,000
$19.74
$197.35K
Liawatidewi Yakob
17 May 2021
SVP Corp Admin Center
Sold after exercise
9,637
$19.99
$192.69K
Zhou Rong
14 May 2021
EVP, Production Center
Sold after exercise
17,419
$19.72
$343.46K
ZASLOFF MICHAEL A
13 May 2021
Director
Sold after exercise
25,827
$19.34
$499.43K
Zhou Rong
13 May 2021
EVP, Production Center
Sold after exercise
700
$19.58
$13.71K
Liawatidewi Yakob
11 May 2021
EVP Corp Admin Center
Sold after exercise
10,000
$19.06
$190.60K
PRINS RICHARD K
11 May 2021
Director
Sold after exercise
15,827
$18.90
$299.11K
Liawatidewi Yakob
21 Jul 2020
EVP Corp Admin Center
Sold after exercise
5,978
$21.22
$126.84K
Liawatidewi Yakob
20 Jul 2020
EVP Corp Admin Center
Sold after exercise
4,186
$21.03
$88.05K
PETERS WILLIAM J
6 Jul 2020
CFO, SVP & Treasurer
Sold after exercise
13,656
$22.00
$300.40K
Liawatidewi Yakob
9 Jun 2020
EVP Corp Admin Center
Sold after exercise
23,405
$20.41
$477.60K
Zhou Rong
4 Jun 2020
EVP, Production Center
Sold after exercise
9,806
$19.19
$188.18K
Zhou Rong
3 Jun 2020
EVP, Production Center
Sold after exercise
13,163
$18.82
$247.68K
Koo Richard
27 May 2020
Director
Sold after exercise
47,782
$18.18
$868.89K
Lee Howard
26 May 2020
Director
Sold after exercise
10,000
$18.60
$185.99K
Lee Howard
22 May 2020
Director
Sold after exercise
10,000
$18.36
$183.64K
Lee Howard
21 May 2020
Director
Sold after exercise
10,000
$18.47
$184.69K
Lee Howard
20 May 2020
Director
Sold after exercise
17,782
$18.43
$327.78K
Petersen Floyd F.
15 May 2020
Director
Sold after exercise
42,682
$18.25
$778.97K
ZASLOFF MICHAEL A
15 May 2020
Director
Sold after exercise
22,950
$18.03
$413.68K
Petersen Floyd F.
14 May 2020
Director
Sold after exercise
5,000
$17.78
$88.88K
ZASLOFF MICHAEL A
14 May 2020
Director
Sold after exercise
14,832
$18.00
$266.98K
Petersen Floyd F.
12 May 2020
Director
Sold after exercise
100
$19.20
$1.92K
PRINS RICHARD K
12 May 2020
Director
Sold after exercise
30,282
$19.00
$575.42K
ZASLOFF MICHAEL A
12 May 2020
Director
Sold after exercise
10,000
$19.00
$190.00K
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