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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

81
Insider
Date
Role
Action
Shares
Price
Amount
Zhou Rong
2 Sep 2026
SENIOR EVP, PRODUCTION CENTER
Sell
3,187
$23.63
$75.31K
PRINS RICHARD K
11 Aug 2026
Director
Sell
7,973
$20.30
$161.85K
Petersen Floyd F.
12 Dec 2025
Director
Sell
2,426
$25.92
$62.89K
Petersen Floyd F.
11 Dec 2025
Director
Sell
1,737
$25.69
$44.62K
Petersen Floyd F.
5 Sep 2024
Director
Sell
3,000
$46.47
$139.42K
Petersen Floyd F.
10 Jun 2024
Director
Sell
3,000
$41.40
$124.20K
ZASLOFF MICHAEL A
5 Mar 2024
Director
Sell
3,111
$47.53
$147.85K
ZASLOFF MICHAEL A
5 Mar 2024
Director
Sell
9,389
$47.06
$441.87K
PRINS RICHARD K
17 Nov 2023
Director
Sell
4,000
$55.86
$223.45K
Deflin Gayle
14 Nov 2023
Director
Sell
4,163
$55.45
$230.84K
PRINS RICHARD K
13 Nov 2023
Director
Sell
5,000
$52.50
$262.50K
PRINS RICHARD K
18 Aug 2023
Director
Sell
2,000
$52.50
$105.01K
PRINS RICHARD K
15 Aug 2023
Director
Sell
4,163
$57.39
$238.91K
ZASLOFF MICHAEL A
15 Aug 2023
Director
Sell
12,759
$57.22
$730.03K
Deflin Gayle
18 May 2023
Director
Sell
4,519
$44.01
$198.89K
Petersen Floyd F.
17 May 2023
Director
Sell
5,000
$43.13
$215.66K
ZASLOFF MICHAEL A
15 May 2023
Director
Sell
7,500
$42.18
$316.34K
Deflin Gayle
15 May 2023
Director
Sell
1,500
$43.15
$64.73K
Petersen Floyd F.
1 Mar 2023
Director
Sell
87
$37.25
$3.24K
Petersen Floyd F.
1 Mar 2023
Director
Sell
412
$36.59
$15.07K
Petersen Floyd F.
1 Mar 2023
Director
Sell
1
$33.70
$33.70
Petersen Floyd F.
1 Feb 2023
Director
Sell
500
$30.35
$15.18K
Petersen Floyd F.
3 Jan 2023
Director
Sell
500
$27.94
$13.97K
Petersen Floyd F.
1 Dec 2022
Director
Sell
500
$30.13
$15.07K
Petersen Floyd F.
1 Nov 2022
Director
Sell
500
$31.13
$15.57K
Petersen Floyd F.
3 Oct 2022
Director
Sell
500
$28.59
$14.30K
Petersen Floyd F.
1 Sep 2022
Director
Sell
500
$29.44
$14.72K
Petersen Floyd F.
1 Aug 2022
Director
Sell
500
$37.48
$18.74K
Petersen Floyd F.
1 Jul 2022
Director
Sell
500
$34.78
$17.39K
PETERS WILLIAM J
17 Jun 2022
CFO, EVP & Treasurer
Sell
5,512
$32.05
$176.68K
Petersen Floyd F.
1 Jun 2022
Director
Sell
120
$37.67
$4.52K
Petersen Floyd F.
1 Jun 2022
Director
Sell
380
$36.79
$13.98K
Zhang Jack Y.
20 May 2022
CEO & Chief Scientific Officer
Sell
10,650
$34.21
$364.37K
Zhang Jack Y.
19 May 2022
CEO & Chief Scientific Officer
Sell
115
$34.28
$3.94K
Zhang Jack Y.
19 May 2022
CEO & Chief Scientific Officer
Sell
41,615
$33.76
$1.40M
Zhang Jack Y.
18 May 2022
CEO & Chief Scientific Officer
Sell
2,006
$35.78
$71.78K
Zhang Jack Y.
18 May 2022
CEO & Chief Scientific Officer
Sell
9,776
$34.77
$339.93K
Zhang Jack Y.
18 May 2022
CEO & Chief Scientific Officer
Sell
55,264
$33.97
$1.88M
Zhang Jack Y.
17 May 2022
CEO & Chief Scientific Officer
Sell
2,837
$36.14
$102.53K
Zhang Jack Y.
17 May 2022
CEO & Chief Scientific Officer
Sell
47,539
$35.74
$1.70M
Zhang Jack Y.
16 May 2022
CEO & Chief Scientific Officer
Sell
13,795
$36.41
$502.27K
Zhang Jack Y.
16 May 2022
CEO & Chief Scientific Officer
Sell
54,274
$35.58
$1.93M
Petersen Floyd F.
2 May 2022
Director
Sell
27
$35.52
$958.91
Petersen Floyd F.
2 May 2022
Director
Sell
268
$35.15
$9.42K
Petersen Floyd F.
1 Apr 2022
Director
Sell
63
$37.35
$2.35K
Petersen Floyd F.
1 Apr 2022
Director
Sell
437
$36.59
$15.99K
PETERS WILLIAM J
15 Mar 2022
CFO, EVP & Treasurer
Sell
7,900
$34.46
$272.25K
Petersen Floyd F.
1 Mar 2022
Director
Sell
500
$27.27
$13.64K
Petersen Floyd F.
1 Feb 2022
Director
Sell
411
$24.24
$9.96K
Petersen Floyd F.
1 Feb 2022
Director
Sell
89
$23.37
$2.08K
Petersen Floyd F.
3 Jan 2022
Director
Sell
500
$23.22
$11.61K
Petersen Floyd F.
22 Dec 2021
Director
Sell
1,000
$22.50
$22.50K
PETERS WILLIAM J
16 Aug 2021
CFO, EVP & Treasurer
Sell
6,589
$19.35
$127.52K
Zhou Rong
9 Jun 2021
EVP, Production Center
Sell
4,732
$19.58
$92.65K
Liawatidewi Yakob
14 May 2021
SVP Corp Admin Center
Sell
3,186
$19.92
$63.45K
Liawatidewi Yakob
12 May 2021
EVP Corp Admin Center
Sell
4,592
$19.33
$88.74K
PETERS WILLIAM J
15 Mar 2021
CFO, SVP & Treasurer
Sell
4,244
$19.03
$80.75K
Zhang Jack Y.
18 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
407
$18.58
$7.56K
Zhang Jack Y.
17 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
13,801
$18.67
$257.72K
Zhang Jack Y.
16 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
16,259
$18.51
$301.03K
Zhang Jack Y.
12 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
13,277
$18.94
$251.52K
Zhang Jack Y.
11 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
19,823
$19.06
$377.88K
Zhang Jack Y.
10 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
15,747
$18.76
$295.34K
Zhang Jack Y.
9 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
11,927
$18.93
$225.78K
Zhang Jack Y.
8 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
13,452
$18.89
$254.05K
Zhang Jack Y.
5 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
15,507
$18.94
$293.72K
Zhang Jack Y.
4 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
25,570
$18.89
$483.02K
Zhang Jack Y.
3 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
16,299
$18.36
$299.32K
Zhang Jack Y.
2 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
13,817
$18.66
$257.82K
Petersen Floyd F.
1 Feb 2021
Director
Sell
639
$18.26
$11.67K
Zhang Jack Y.
1 Feb 2021
CEO & Chief Scientific Officer
Sell indirect
24,114
$18.29
$441.12K
PETERS WILLIAM J
19 Jan 2021
CFO, SVP & Treasurer
Sell
6,495
$18.67
$121.24K
Petersen Floyd F.
1 Dec 2020
Director
Sell
500
$17.87
$8.94K
Petersen Floyd F.
2 Nov 2020
Director
Sell
500
$19.84
$9.92K
Petersen Floyd F.
1 Oct 2020
Director
Sell
500
$18.89
$9.45K
Petersen Floyd F.
1 Sep 2020
Director
Sell
500
$19.90
$9.95K
PETERS WILLIAM J
14 Aug 2020
CFO, SVP & Treasurer
Sell
5,512
$20.36
$112.22K
PRINS RICHARD K
11 Aug 2020
Director
Sell
6,000
$20.33
$121.98K
Petersen Floyd F.
3 Aug 2020
Director
Sell
500
$20.62
$10.31K
Petersen Floyd F.
1 Jul 2020
Director
Sell
500
$22.27
$11.14K
Petersen Floyd F.
1 Jun 2020
Director
Sell
500
$18.97
$9.48K
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