X0609 4 2026-09-01 0000751978 VICOR CORP VICR 0001512868 Davies Philip D false 25 FRONTAGE ROAD ANDOVER MA 01810 true true false false Corp. VP-Global Sales & Mktg. true Common Stock 2026-09-01 4 M false 3073 41.6100 A 4993 D Common Stock 2026-09-01 4 S false 1173 176.5922 D 3820 D Common Stock 2026-09-01 4 S false 1100 177.6312 D 2720 D Common Stock 2026-09-01 4 S false 700 178.6600 D 2020 D Common Stock 2026-09-01 4 S false 100 184.8500 D 1920 D Non Qualified Stock Option 41.61 2026-09-01 4 M false 3073 0 D 2026-05-02 2028-05-02 Common Stock 3073 856 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 $176.0000 and $176.9900. The reporting person undertakes to provide to Vicor Corporation, any security holder of Vicor Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) through (5) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $177.3000 to $177.8800. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $178.4300 to $179.0400. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $184.8500 to $184.8500. /s/Quentin A. Fendelet Attorney in Fact for Philip D. Davies 2026-09-03