X0609 4 2026-10-01 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 2026-10-01 4 M false 856 41.6100 A 2776 D Common Stock 2026-10-01 4 M false 2216 33.9600 A 4992 D Common Stock 2026-10-01 4 S false 200 307.0850 D 4792 D Common Stock 2026-10-01 4 S false 272 308.4879 D 4520 D Common Stock 2026-10-01 4 S false 100 311.8300 D 4420 D Common Stock 2026-10-01 4 S false 100 313.2000 D 4320 D Common Stock 2026-10-01 4 S false 300 314.8367 D 4020 D Common Stock 2026-10-01 4 S false 300 316.2567 D 3720 D Common Stock 2026-10-01 4 S false 500 317.3240 D 3220 D Common Stock 2026-10-01 4 S false 400 318.2950 D 2820 D Common Stock 2026-10-01 4 S false 299 319.6653 D 2521 D Common Stock 2026-10-01 4 S false 201 320.1776 D 2320 D Common Stock 2026-10-01 4 S false 400 322.0250 D 1920 D Non Qualified Stock Option 41.6100 2026-10-01 4 M false 856 0 D 2026-05-02 2028-05-02 Common Stock 856 7678 D Non Qualified Stock Option 33.9600 2026-10-01 4 M false 2216 0 D 2025-05-03 2027-05-03 Common Stock 2216 35646 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 $306.9900 and $307.1800. 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 (12) 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 $308.3000 to $308.6400. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $311.8300 to $311.8300. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $313.2000 to $313.2000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $314.6200 to $315.0700. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $315.6600 to $316.6000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $317.0200 to $317.9000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $318.0200 to $318.9200. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $319.0700 to $320.0000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $320.0700 to $320.7000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $321.7100 to $322.3200. /s/Quentin A. Fendelet Attorney in Fact for Philip D. Davies 2026-10-05