SEC Insider Transactions from Stefan Constantin Ionel.

Last updated: 2026-03-14 11:56 UTC | Total transactions: 42

Stefan Constantin Ionel, Chief Technology Officer at Amprius Technologies ($AMPX), sold common shares on the open market nine times over the last year, totaling about $10.1 million. His most recent sale occurred on February 23, 2026. These transactions rank 1,115th among 11,678 insiders in our database, surpassing the average sale value of $8.6 million and 6.4 transactions per insider. He made no open market purchases in this period.

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Transaction Date Company Ticker Insider Name Title Transaction Type Security Shares Price Shares Owned Following Total Shares Outstanding % of Owned % of Outstanding
March 4, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer A Common stock 110000 $0.00 833,330.0000 130,483,838 15.21% 0.08%
Feb. 23, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 25366 $10.16 723,330.0000 130,483,838 3.39% 0.02%
Jan. 28, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Stock Option (right to buy) 90 $0.00 0.0000 130,483,838 100.00% 0.00%
Jan. 28, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 39690 $12.00 748,696.0000 130,483,838 5.03% 0.03%
Jan. 28, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Common stock 39600 $0.05 788,386.0000 130,483,838 5.29% 0.03%
Jan. 28, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Stock Option (right to buy) 39600 $0.00 0.0000 130,483,838 100.00% 0.03%
Jan. 28, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Common stock 90 $0.62 748,786.0000 130,483,838 0.01% 0.00%
Jan. 23, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Common stock 1600 $0.05 750,296.0000 130,483,838 0.21% 0.00%
Jan. 21, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Common stock 41563 $0.62 790,259.0000 130,483,838 5.55% 0.03%
Jan. 21, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Common stock 15834 $0.05 806,093.0000 130,483,838 2.00% 0.01%
Jan. 21, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Common stock 15883 $0.05 821,976.0000 130,483,838 1.97% 0.01%
Jan. 21, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 73280 $12.00 748,696.0000 130,483,838 8.92% 0.06%
Jan. 22, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Common stock 253928 $0.05 1,002,624.0000 130,483,838 33.92% 0.19%
Jan. 22, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Common stock 72795 $0.45 1,075,419.0000 130,483,838 7.26% 0.06%
Jan. 22, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Common stock 166104 $0.05 1,241,523.0000 130,483,838 15.45% 0.13%
Jan. 22, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 492827 $12.04 748,696.0000 130,483,838 39.70% 0.38%
Jan. 23, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 1600 $12.00 748,696.0000 130,483,838 0.21% 0.00%
Jan. 21, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Stock Option (right to buy) 41563 $0.00 90.0000 130,483,838 99.78% 0.03%
Jan. 21, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Stock Option (right to buy) 15834 $0.00 295,128.0000 130,483,838 5.09% 0.01%
Jan. 21, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Stock Option (right to buy) 15883 $0.00 166,104.0000 130,483,838 8.73% 0.01%
Jan. 22, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Stock Option (right to buy) 253928 $0.00 41,200.0000 130,483,838 86.04% 0.19%
Jan. 22, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Stock Option (right to buy) 72795 $0.00 0.0000 130,483,838 100.00% 0.06%
Jan. 22, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Stock Option (right to buy) 166104 $0.00 0.0000 130,483,838 100.00% 0.13%
Jan. 23, 2026 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Stock Option (right to buy) 1600 $0.00 39,600.0000 130,483,838 3.88% 0.00%
Dec. 11, 2025 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 198255 $10.51 748,696.0000 130,483,838 20.94% 0.15%
Dec. 11, 2025 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Common stock 125000 $0.05 946,951.0000 130,483,838 15.21% 0.10%
Dec. 11, 2025 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Stock Option (right to buy) 125000 $0.00 310,962.0000 130,483,838 28.67% 0.10%
Nov. 21, 2025 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 25024 $10.08 821,951.0000 130,483,838 2.95% 0.02%
Aug. 21, 2025 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 19159 $6.82 846,975.0000 117,926,808 2.21% 0.02%
May 21, 2025 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 20366 $2.43 866,134.0000 117,926,808 2.30% 0.02%
March 19, 2025 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer A Common stock 461540 $0.00 886,500.0000 117,926,808 108.61% 0.39%
March 14, 2025 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Stock Option (right to buy) 3471 $0.00 0.0000 117,926,808 100.00% 0.00%
March 14, 2025 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer M Common stock 3471 $0.98 424,960.0000 117,926,808 0.82% 0.00%
Feb. 21, 2025 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 9066 $3.13 421,489.0000 0 2.11% 0.00%
Nov. 21, 2024 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 8575 $1.96 430,555.0000 0 1.95% 0.00%
Oct. 23, 2024 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer A Stock Option (right to buy) 139613 $0.00 139,613.0000 0 9999.99% 0.00%
Oct. 23, 2024 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer A Stock Option (right to buy) 41653 $0.00 41,653.0000 0 9999.99% 0.00%
Oct. 23, 2024 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer A Stock Option (right to buy) 3471 $0.00 3,471.0000 0 9999.99% 0.00%
Aug. 21, 2024 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 8800 $1.04 386,168.0000 0 2.23% 0.00%
May 21, 2024 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 5272 $1.33 399,089.0000 0 1.30% 0.00%
May 22, 2024 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer S Common stock 4121 $1.36 394,968.0000 0 1.03% 0.00%
March 19, 2024 Amprius Technologies, Inc. $AMPX Stefan Constantin Ionel Chief Technology Officer A Common stock 374570 $0.00 404,361.0000 0 1257.33% 0.00%