X0609 4 2026-06-16 0 0000751978 VICOR CORP vicr 0000901484 VINCIARELLI PATRIZIO false C/O VICOR CORPORATION 25 FRONTAGE ROAD ANDOVER MA 01810 1 1 1 0 Chairman and CEO 1 Common Stock 167125 I See footnote Common Stock 2026-06-16 4 S 0 1180 320.0291 D 8586910 D Common Stock 2026-06-16 4 S 0 400 321.0244 D 8586510 D Common Stock 2026-06-16 4 S 0 1001 322.8182 D 8585509 D Common Stock 2026-06-16 4 S 0 2745 324.2447 D 8582764 D Common Stock 2026-06-16 4 S 0 1770 325.3986 D 8580994 D Common Stock 2026-06-16 4 S 0 2884 326.3244 D 8578110 D Common Stock 2026-06-16 4 S 0 1901 327.3452 D 8576209 D Common Stock 2026-06-16 4 S 0 1400 328.879 D 8574809 D Common Stock 2026-06-16 4 S 0 2896 329.9204 D 8571913 D Common Stock 2026-06-16 4 S 0 405 331.2283 D 8571508 D Common Stock 2026-06-16 4 S 0 200 332.245 D 8571308 D Common Stock 2026-06-16 4 S 0 600 335.08 D 8570708 D Common Stock 2026-06-16 4 S 0 400 337.1323 D 8570308 D Common Stock 2026-06-16 4 S 0 718 338.3934 D 8569590 D Common Stock 2026-06-16 4 S 0 900 339.3556 D 8568690 D Common Stock 2026-06-16 4 S 0 200 340.22 D 8568490 D Common Stock 2026-06-16 4 S 0 400 341.735 D 8568090 D These shares are held by the reporting person as Trustee of the Patrizio Vinciarelli Irrevocable Trust U/A Dated 12/21/2012, established for the benefit of the child of the reporting person. This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on February 26, 2026. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $319.6600 and $320.3700. 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 (3) through (19) 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 $320.9000 and $321.2850. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $322.5600 and $323.5400. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $323.7400 and $324.6300. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $324.7800 and $325.7700. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $325.8200 and $326.7200. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $327.0400 and $328.0000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $328.2750 and $329.2600. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $329.2900 and $330.2700. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $330.2900 and $331.2500. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $332.2400 and $332.2500. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $334.7900 and $335.2300. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $336.5500 and $337.3050. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $338.0500 and $338.7300. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $339.1900 and $339.7300 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $340.2100 and $340.2300. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $341.6700 and $341.8000 /s/Quentin A. Fendelet. Attorney in fact for Patrizio Vinciarelli 2026-06-17