X0609 4 2026-05-01 0 0000751978 VICOR CORP vicr 0001512868 Davies Philip D false 25 FRONTAGE RD. ANDOVER MA 01810 1 1 0 0 VP Global Sales & Marketing 1 Common Stock 2026-05-01 4 M 0 3073 30.98 A 4993 D Common Stock 2026-05-01 4 S 0 100 264.07 D 4893 D Common Stock 2026-05-01 4 S 0 400 266.505 D 4493 D Common Stock 2026-05-01 4 S 0 800 268.4 D 3693 D Common Stock 2026-05-01 4 S 0 1173 269.3865 D 2520 D Common Stock 2026-05-01 4 S 0 200 270.31 D 2320 D Common Stock 2026-05-01 4 S 0 200 271.53 D 2120 D Common Stock 2026-05-01 4 S 0 100 273.21 D 2020 D Common Stock 2026-05-01 4 S 0 100 274.43 D 1920 D Non Qualified Stock Option 30.98 2026-05-01 4 M 0 3073 0 D 2029-09-06 Common Stock 3073 5466 D This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 21, 2025. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $264.0700 to $264.0700. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $266.2200 to $266.9400. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $267.6900 to $268.6800 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $268.8100 to $269.7700. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $270.1100 to $270.5100. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $271.4400 to $271.6200. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $273.2100 to $273.2100. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $274.4300 to $274.4300. Options granted on 9/6/2019 and vest over five years. /s/Quentin A. Fendelet Attorney in fact for Philip D. Davies 2026-05-04