X0609 4 2026-04-09 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 171125 I See footnote Common Stock 2026-04-09 4 S 0 4721 186 D 8980263 D Common Stock 2026-04-09 4 S 0 10000 187 D 8970263 D Common Stock 2026-04-09 4 S 0 10000 188 D 8960263 D Common Stock 2026-04-09 4 S 0 222 189 D 8960041 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 November 3, 2025. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $186.0000 to $186.0000. 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 (6) 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 $187.0000 to $187.0000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $188.0000 to $188.0000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $189.0000 to $189.0000. /s/Quentin A. Fendelet. Attorney in fact for Patrizio Vinciarelli 2026-04-10