X0609 4 2026-10-02 0000751978 VICOR CORP VICR 0000901484 VINCIARELLI PATRIZIO false 25 FRONTAGE ROAD ANDOVER MA 01810 true true true false Chairman & CEO true Common Stock 167125 I See Footnote Common Stock 2026-10-02 2026-10-02 4 S false 1075 306.9256 D 8326315 D Common Stock 2026-10-02 2026-10-02 4 S false 4961 308.0112 D 8321354 D Common Stock 2026-10-02 2026-10-02 4 S false 877 309.0983 D 8320477 D Common Stock 2026-10-02 2026-10-02 4 S false 6448 310.3220 D 8314029 D Common Stock 2026-10-02 2026-10-02 4 S false 2679 311.4240 D 8311350 D Common Stock 2026-10-02 2026-10-02 4 S false 2648 312.2882 D 8308702 D Common Stock 2026-10-02 2026-10-02 4 S false 1312 313.3191 D 8307390 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 $306.5100 and $307.3600. 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 (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 $307.5500 and $308.1800. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $308.7000 and $309.6800. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $309.8500 and $310.7000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $310.9000 and $311.8100. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $312.0000 and $312.4600. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $313.3000 and $313.5600. /s/Quentin A. Fendelet Attorney in Fact for Patrizio Vinciarelli 2026-10-05