X0609 4 2026-06-15 0 0000751978 VICOR CORP VICR 0000901484 VINCIARELLI PATRIZIO false C/O VICOR CORPORATION 25 FRONTAGE ROAD ANDOVER MA 01810 1 1 1 0 Chairman & CEO 1 Common Stock 167125 I See Footnote Common Stock 2026-06-15 4 S 0 600 309.23 D 8607490 D Common Stock 2026-06-15 4 S 0 400 309.605 D 8607090 D Common Stock 2026-06-15 4 S 0 755 311.707 D 8606335 D Common Stock 2026-06-15 4 S 0 645 312.8242 D 8605690 D Common Stock 2026-06-15 4 S 0 846 314.375 D 8604844 D Common Stock 2026-06-15 4 S 0 954 315.0559 D 8603890 D Common Stock 2026-06-15 4 S 0 1703 316.1758 D 8602187 D Common Stock 2026-06-15 4 S 0 2297 317.4637 D 8599890 D Common Stock 2026-06-15 4 S 0 2000 318.124 D 8597890 D Common Stock 2026-06-15 4 S 0 100 318.83 D 8597790 D Common Stock 2026-06-15 4 S 0 2510 320.4428 D 8595280 D Common Stock 2026-06-15 4 S 0 3990 321.4479 D 8591290 D Common Stock 2026-06-15 4 S 0 1800 322.5761 D 8589490 D Common Stock 2026-06-15 4 S 0 400 323.5075 D 8589090 D Common Stock 2026-06-15 4 S 0 600 324.81 D 8588490 D Common Stock 2026-06-15 4 S 0 200 330.05 D 8588290 D Common Stock 2026-06-15 4 S 0 200 331.7 D 8588090 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 $308.5100 and $309.3400. 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 $309.5100 and $309.7000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $311.2000 and $312.1500. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $312.2350 and $312.9800. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $313.6900 and $314.6800. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $314.6900 and $315.5100. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $315.7800 and $316.7700. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $316.8200 and $317.8000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $317.8300 and $318.7200. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $318.8300 and $318.8300. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $319.8900 and $320.8200. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $320.9500 and $321.8900. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $322.1900 and $323.1200. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $323.2400 and $323.7800. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $324.6300 and $324.9000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $330.0500 and $330.0500. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $331.3500 and $332.0500. /s/Quentin A. Fendelet Attorney in fact for Patrizio Vinciarelli 2026-06-16