X0508 4 2026-03-11 0000751978 VICOR CORP VICR 0001866281 Schmidt James F C/O VICOR CORPORATION 25 FRONTAGE RD. ANDOVER MA 01810 true true false false CFO, Treasurer, Secretary true Common Stock 2026-03-11 4 M false 15000 93.33 A 15000 D Common Stock 2026-03-11 4 M false 500 48.38 A 15500 D Common Stock 2026-03-11 4 S false 900 169.48 D 14600 D Common Stock 2026-03-11 4 S false 800 172.9638 D 13800 D Common Stock 2026-03-11 4 S false 300 174.4133 D 13500 D Common Stock 2026-03-11 4 S false 1997 176.3531 D 11503 D Common Stock 2026-03-11 4 S false 4401 177.5735 D 7102 D Common Stock 2026-03-11 4 S false 5157 178.4011 D 1945 D Common Stock 2026-03-11 4 S false 1245 179.2188 D 700 D Common Stock 2026-03-11 4 S false 700 180.4614 D 0 D Non Qualified Stock Option 93.33 2026-03-11 4 M false 15000 0 D 2025-06-01 2031-06-01 Common Stock 15000 5000 D Non Qualified Stock Option 48.38 2026-03-11 4 M false 500 0 D 2026-01-16 2028-01-16 Common Stock 500 0 D This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 10, 2025. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $169.4300 to $169.5300. 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 (9) 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 $172.8300 to $173.0400. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $174.3800 to $174.4400. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $175.9500 to $176.9200. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $176.9700 to $177.9300. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $177.9900 to $178.9000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $178.9900 to $179.9500. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $180.1500 to $180.5600. /s/Kemble D. Morrison. Attorney in fact for James F. Schmidt 2026-03-12