InsiderClue
← All stocks

Amprius Technologies, Inc.

AMPX Net selling
CIK 0001899287 #2254 in the set updated 17 Sep 2026
Bought (120 mo)
$0.00
out of their own pocket, the only kind of buying there is
Sold (120 mo)
$98.48M
$0.00 on a plan · $77.87M straight out of an exercise
Sold at will
$20.62M
87 of 122 sales
Net
−$98.48M
−$20.62M against sales at will

By person

15 insiders · 127 transactions
19.3×

Thomas M. Stepien holds 19.3 times base salary in stock. $6.18M of shares against $319.71K in salary for 2025.

Salary from the company's own proxy. The shares are what Thomas M. Stepien last reported holding, valued at $10.03, the price Common stock was last bought or sold at on the open market here, on 24 Aug 2026.

Insider
Role
Bought
Sold
Net
Holding
Of company
Worth
Change
Sun Kang
Director
—
$58.50M (20) scheduled
−$58.50M
1,274,803
0.8727%
$12.79M
—
Stefan Constantin Ionel
Chief Technology Officer
—
$11.24M (19) scheduled
−$11.24M
771,629
0.5282%
$7.74M
+1,357%
HSIEH Wen Hsuan
Director
—
$7.62M (2) scheduled
−$7.62M
44,444
0.0304%
$445.77K
—
Chu Steven
Director
—
$5.86M (4) scheduled
−$5.86M
137,762
0.0943%
$1.38M
+5,410%
MIRRO JUSTIN E
Director
—
$5.06M (32)
−$5.06M
1,337,895
0.9159%
$13.42M
+12.0%
Bornstein Jonathan
President of Amprius Lab
—
$4.84M (25) scheduled
−$4.84M
1,463,618
1.00%
$14.68M
+1,205%
DIXON DONALD R
Director
—
$2.54M (3)
−$2.54M
639,459
0.4377%
$6.41M
+9.4%
Stepien Thomas M
Chief Executive Officer
—
$1.34M (5)
−$1.34M
616,010
0.4217%
$6.18M
+6,060%
Amprius, Inc. entity
10% owner
—
$1.09M (5)
−$1.09M
2,500,071
1.71%
$25.08M
−96.2%
Wallach Sandra
Chief Financial Officer
—
$394.67K (7)
−$394.67K
1,005,275
0.6882%
$10.08M
—
RODRIGUEZ RICARDO C.
Chief Financial Officer
—
—
—
350,000
0.2396%
$3.51M
—
SATTERTHWAITE LIVINGSTON
Director
—
—
—
346,506
0.2372%
$3.48M
+3,920%
BAYLESS KATHLEEN A
Director
—
—
—
216,120
0.1479%
$2.17M
—
Gustanski Mary
Director
—
—
—
146,396
0.1002%
$1.47M
—
Kensington Capital Sponsor IV LLC entity
Former 10% holder (see ftn 2)
—
—
—
0
0.0000%
$0.00
−100.0%

Individual transactions

127
Insider
Date
Role
Action
Shares
Price
Amount
Stepien Thomas M
24 Aug 2026
Chief Executive Officer
Sell
8,000
$10.03
$80.24K
Stepien Thomas M
21 Aug 2026
Chief Executive Officer
Sell
23,529
$10.34
$243.31K
Stefan Constantin Ionel
21 Aug 2026
Chief Technology Officer
Sell
29,681
$10.34
$306.93K
Sun Kang
21 Aug 2026
Director
Sell
62,101
$10.34
$642.19K
DIXON DONALD R
15 Jun 2026
Director
Sell indirect
85,000
$17.17
$1.46M
DIXON DONALD R
9 Jun 2026
Director
Sell indirect
40,000
$19.13
$765.20K
Stepien Thomas M
4 Jun 2026
Chief Executive Officer
Sell
2,000
$20.97
$41.94K
Stefan Constantin Ionel
27 May 2026
Chief Technology Officer
Sell
3,208
$17.19
$55.16K
Stepien Thomas M
27 May 2026
Chief Executive Officer
Sell
4,375
$17.19
$75.22K
Sun Kang
27 May 2026
Director
Sell
356
$17.19
$6.12K
DIXON DONALD R
26 May 2026
Director
Sell indirect
17,895
$17.90
$320.25K
Stepien Thomas M
21 May 2026
Chief Executive Officer
Sell
60,702
$14.79
$897.69K
Stefan Constantin Ionel
21 May 2026
Chief Technology Officer
Sell
28,812
$14.79
$426.08K
Sun Kang
21 May 2026
Director
Sell
67,796
$14.79
$1.00M
Sun Kang
1 Apr 2026
Director
Sold after exercise
249,037
$16.78
$4.18M
Sun Kang
1 Apr 2026
Director
Sold after exercise
1,250,963
$15.73
$19.68M
Sun Kang
23 Mar 2026
Director
Sell indirect
65,046
$19.06
$1.24M
Sun Kang
23 Mar 2026
Director
Sell indirect
152,823
$18.69
$2.86M
Chu Steven
12 Mar 2026
Director
Sold after exercise
5,565
$18.53
$103.15K
Chu Steven
12 Mar 2026
Director
Sold after exercise
50,000
$18.21
$910.74K
Chu Steven
12 Mar 2026
Director
Sold after exercise
100,000
$18.65
$1.86M
HSIEH Wen Hsuan
12 Mar 2026
Director
Sold after exercise
130,646
$18.22
$2.38M
HSIEH Wen Hsuan
12 Mar 2026
Director
Sold after exercise
282,500
$18.55
$5.24M
Chu Steven
10 Mar 2026
Director
Sold after exercise
166,632
$17.92
$2.99M
Stefan Constantin Ionel
23 Feb 2026
Chief Technology Officer
Sell
25,366
$10.16
$257.60K
Sun Kang
23 Feb 2026
Director
Sell
61,251
$10.16
$622.03K
Stefan Constantin Ionel
28 Jan 2026
Chief Technology Officer
Sold after exercise
39,690
$12.00
$476.35K
Stefan Constantin Ionel
23 Jan 2026
Chief Technology Officer
Sold after exercise
1,600
$12.00
$19.20K
Stefan Constantin Ionel
22 Jan 2026
Chief Technology Officer
Sold after exercise
492,827
$12.04
$5.93M
Stefan Constantin Ionel
21 Jan 2026
Chief Technology Officer
Sold after exercise
73,280
$12.00
$879.41K
Sun Kang
20 Jan 2026
Director
Sold after exercise
43,185
$11.03
$476.27K
Sun Kang
16 Jan 2026
Director
Sold after exercise
950,548
$11.07
$10.52M
Sun Kang
12 Jan 2026
Director
Sold after exercise
506,267
$10.10
$5.11M
Stefan Constantin Ionel
11 Dec 2025
Chief Technology Officer
Sold after exercise
198,255
$10.51
$2.08M
Sun Kang
21 Nov 2025
Chief Executive Officer
Sell
68,655
$10.08
$692.13K
Stefan Constantin Ionel
21 Nov 2025
Chief Technology Officer
Sell
25,024
$10.08
$252.27K
Sun Kang
17 Nov 2025
Chief Executive Officer
Sold after exercise
1,000,000
$10.60
$10.60M
Sun Kang
21 Aug 2025
Chief Executive Officer
Sell
65,654
$6.82
$447.51K
Wallach Sandra
21 Aug 2025
Chief Financial Officer
Sell
28,390
$6.82
$193.51K
Stefan Constantin Ionel
21 Aug 2025
Chief Technology Officer
Sell
19,159
$6.82
$130.59K
Sun Kang
21 May 2025
Chief Executive Officer
Sell
69,786
$2.43
$169.72K
Wallach Sandra
21 May 2025
Chief Financial Officer
Sell
27,595
$2.43
$67.11K
Stefan Constantin Ionel
21 May 2025
Chief Technology Officer
Sell
20,366
$2.43
$49.53K
Stefan Constantin Ionel
14 Mar 2025
Chief Technology Officer
Exercised, kept
3,471
$0.98
$3.40K
Bornstein Jonathan
10 Mar 2025
President of Amprius Lab
Exercised, kept
3,471
$0.98
$3.40K
Bornstein Jonathan
21 Feb 2025
President of Amprius Lab
Sell
13,527
$3.13
$42.38K
Stefan Constantin Ionel
21 Feb 2025
Chief Technology Officer
Sell
9,066
$3.13
$28.41K
Wallach Sandra
21 Feb 2025
Chief Financial Officer
Sell
18,142
$3.13
$56.84K
Sun Kang
21 Feb 2025
Chief Executive Officer
Sell
34,353
$3.13
$107.63K
Stefan Constantin Ionel
21 Nov 2024
Chief Technology Officer
Sell
8,575
$1.96
$16.85K
Wallach Sandra
21 Nov 2024
Chief Financial Officer
Sell
17,158
$1.96
$33.71K
Bornstein Jonathan
21 Nov 2024
President of Amprius Lab
Sell
18,170
$1.96
$35.70K
Bornstein Jonathan
21 Nov 2024
President of Amprius Lab
Sell indirect
15,000
$1.96
$29.44K
Sun Kang
21 Nov 2024
Chief Executive Officer
Sell
33,779
$1.96
$66.36K
Bornstein Jonathan
20 Nov 2024
President of Amprius Lab
Sell indirect
133,536
$1.92
$256.88K
MIRRO JUSTIN E
5 Sep 2024
Director
Sell indirect
140,000
$0.81
$112.71K
MIRRO JUSTIN E
5 Sep 2024
Director
Sell indirect
110,000
$0.81
$88.55K
Amprius, Inc.
4 Sep 2024
10% owner
Sell
13,255
$0.95
$12.59K
MIRRO JUSTIN E
4 Sep 2024
Director
Sell indirect
175,000
$0.94
$164.78K
MIRRO JUSTIN E
4 Sep 2024
Director
Sell indirect
150,000
$0.94
$140.97K
Amprius, Inc.
3 Sep 2024
10% owner
Sell
6,300
$1.00
$6.30K
MIRRO JUSTIN E
3 Sep 2024
Director
Sell indirect
75,000
$1.00
$74.78K
MIRRO JUSTIN E
3 Sep 2024
Director
Sell indirect
60,000
$1.00
$60.05K
Stefan Constantin Ionel
21 Aug 2024
Chief Technology Officer
Sell
8,800
$1.04
$9.15K
Sun Kang
21 Aug 2024
Chief Executive Officer
Sell
33,333
$1.04
$34.67K
Bornstein Jonathan
21 Aug 2024
President of Amprius Lab
Sell
18,644
$1.04
$19.39K
Wallach Sandra
21 Aug 2024
Chief Financial Officer
Sell
17,606
$1.04
$18.31K
MIRRO JUSTIN E
14 Jun 2024
Director
Sell indirect
65,000
$1.13
$73.52K
MIRRO JUSTIN E
14 Jun 2024
Director
Sell indirect
195,000
$1.13
$220.55K
MIRRO JUSTIN E
13 Jun 2024
Director
Sell indirect
65,000
$1.22
$79.06K
MIRRO JUSTIN E
13 Jun 2024
Director
Sell indirect
195,000
$1.21
$236.59K
MIRRO JUSTIN E
12 Jun 2024
Director
Sell indirect
70,000
$1.30
$90.90K
MIRRO JUSTIN E
12 Jun 2024
Director
Sell indirect
210,000
$1.30
$272.60K
Wallach Sandra
22 May 2024
Chief Financial Officer
Sell
8,245
$1.36
$11.18K
Bornstein Jonathan
22 May 2024
President of Amprius Lab
Sell
8,731
$1.36
$11.84K
Sun Kang
22 May 2024
See Remarks
Sell
15,611
$1.36
$21.17K
Stefan Constantin Ionel
22 May 2024
Chief Technology Officer
Sell
4,121
$1.36
$5.59K
Wallach Sandra
21 May 2024
Chief Financial Officer
Sell
10,549
$1.33
$14.00K
Bornstein Jonathan
21 May 2024
President of Amprius Lab
Sell
11,171
$1.33
$14.83K
Sun Kang
21 May 2024
See Remarks
Sell
19,973
$1.33
$26.52K
Stefan Constantin Ionel
21 May 2024
Chief Technology Officer
Sell
5,272
$1.33
$7.00K
Bornstein Jonathan
12 Apr 2024
President of Amprius Lab
Exercised, kept
1,007,867
$0.05
$50.39K
Bornstein Jonathan
2 Apr 2024
President of Amprius Lab
Sold after exercise
125,983
$2.38
$299.61K
Bornstein Jonathan
6 Mar 2024
President of Amprius Lab
Sold after exercise
40,200
$2.78
$111.58K
Bornstein Jonathan
5 Mar 2024
President of Amprius Lab
Sold after exercise
109,800
$2.92
$320.46K
Bornstein Jonathan
6 Feb 2024
President of Amprius Lab
Sold after exercise
150,000
$4.43
$663.81K
Bornstein Jonathan
2 Jan 2024
President of Amprius Lab
Sold after exercise
25,366
$5.05
$128.08K
Bornstein Jonathan
2 Jan 2024
President of Amprius Lab
Sold after exercise
124,634
$4.32
$538.18K
Amprius, Inc.
15 Dec 2023
10% owner
Sell
100,000
$3.54
$353.60K
MIRRO JUSTIN E
14 Dec 2023
Director
Sell indirect
85,000
$3.56
$302.37K
MIRRO JUSTIN E
14 Dec 2023
Director
Sell indirect
170,000
$3.56
$605.08K
Amprius, Inc.
14 Dec 2023
10% owner
Sell
100,000
$3.55
$354.80K
MIRRO JUSTIN E
13 Dec 2023
Director
Sell indirect
30,000
$3.68
$110.34K
MIRRO JUSTIN E
13 Dec 2023
Director
Sell indirect
60,000
$3.68
$220.78K
Amprius, Inc.
13 Dec 2023
10% owner
Sell
100,000
$3.62
$361.69K
MIRRO JUSTIN E
12 Dec 2023
Director
Sell indirect
20,000
$3.81
$76.21K
MIRRO JUSTIN E
12 Dec 2023
Director
Sell indirect
40,000
$3.81
$152.58K
Bornstein Jonathan
7 Dec 2023
President of Amprius Lab
Sold after exercise
54,477
$3.88
$211.34K
MIRRO JUSTIN E
7 Dec 2023
Director
Sell indirect
10,000
$3.88
$38.81K
MIRRO JUSTIN E
7 Dec 2023
Director
Sell indirect
20,000
$3.88
$77.63K
Bornstein Jonathan
6 Dec 2023
President of Amprius Lab
Sold after exercise
47,767
$4.02
$192.24K
MIRRO JUSTIN E
6 Dec 2023
Director
Sell indirect
10,000
$4.05
$40.49K
MIRRO JUSTIN E
6 Dec 2023
Director
Sell indirect
20,000
$4.05
$80.93K
Bornstein Jonathan
5 Dec 2023
President of Amprius Lab
Sold after exercise
47,756
$4.28
$204.50K
MIRRO JUSTIN E
5 Dec 2023
Director
Sell indirect
10,000
$4.31
$43.07K
MIRRO JUSTIN E
5 Dec 2023
Director
Sell indirect
20,000
$4.33
$86.65K
MIRRO JUSTIN E
30 Nov 2023
Director
Sell indirect
15,000
$4.18
$62.77K
MIRRO JUSTIN E
30 Nov 2023
Director
Sell indirect
30,000
$4.19
$125.59K
MIRRO JUSTIN E
29 Nov 2023
Director
Sell indirect
20,000
$4.01
$80.11K
MIRRO JUSTIN E
29 Nov 2023
Director
Sell indirect
40,000
$4.01
$160.34K
MIRRO JUSTIN E
28 Nov 2023
Director
Sell indirect
15,000
$3.70
$55.55K
MIRRO JUSTIN E
28 Nov 2023
Director
Sell indirect
30,000
$3.71
$111.39K
Bornstein Jonathan
20 Nov 2023
President of Amprius Lab
Sold after exercise
27,631
$3.84
$106.11K
Bornstein Jonathan
9 Nov 2023
President of Amprius Lab
Sold after exercise
49,508
$2.82
$139.65K
Bornstein Jonathan
8 Nov 2023
President of Amprius Lab
Sold after exercise
48,052
$3.05
$146.66K
Bornstein Jonathan
7 Nov 2023
President of Amprius Lab
Sold after exercise
24,809
$3.24
$80.42K
Bornstein Jonathan
12 Oct 2023
President of Amprius Lab
Sold after exercise
22,969
$3.90
$89.69K
Bornstein Jonathan
11 Oct 2023
President of Amprius Lab
Sold after exercise
56,702
$4.16
$236.16K
Bornstein Jonathan
10 Oct 2023
President of Amprius Lab
Sold after exercise
70,329
$4.36
$306.54K
Bornstein Jonathan
20 Sep 2023
President of Amprius Lab
Sold after exercise
6,484
$4.23
$27.40K
Bornstein Jonathan
19 Sep 2023
President of Amprius Lab
Sold after exercise
143,516
$4.37
$627.16K
Stefan Constantin Ionel
15 Sep 2023
Chief Technology Officer
Sell
33,630
$3.89
$130.73K
Stefan Constantin Ionel
14 Sep 2023
Chief Technology Officer
Sell
46,370
$3.66
$169.49K
Stefan Constantin Ionel
9 Sep 2023
Chief Technology Officer
Exercised, kept
80,000
$0.05
$4.00K
MIRRO JUSTIN E
15 Jun 2023
Director
Sell indirect
61,000
$8.85
$540.13K
MIRRO JUSTIN E
14 Jun 2023
Director
Sell indirect
50,000
$9.50
$474.92K
Stefan Constantin Ionel
14 Dec 2022
Chief Technology Officer
Exercised, kept
30,000
$0.05
$1.50K

What was left out

Form 4 filings counted 124
Amendments (4/A) skipped 2
Filings about a different issuer 0
Unreadable filings 0
Joint filings 0
Sales on a Rule 10b5-1 plan 0
Sales straight out of an exercise 35
Sales at will 87
Transactions with no price 0
Shares from compensation/vesting 129,066,266
History held since 16 Sep 2022