X0306 4 2021-09-13 0 0000751978 VICOR CORP vicr 0001403540 Tuozzolo Claudio 25 FRONTAGE ROAD ANDOVER MA 01810 1 1 0 0 Corp. Vice President Common Stock 2021-09-13 4 S 0 1124 124.0785 D 47239 D Common Stock 2021-09-13 4 M 0 1525 17.3038 A 48764 D Common Stock 2021-09-13 4 S 0 810 123.9106 D 47954 D Non Qualified Stock Option 17.3038 2021-09-13 4 M 0 1525 0 D 2023-09-13 Common Stock 1525 0 D This transaction involved the exercise of non-qualified stock options, the terms of which provided for the purchase of shares of common stock possessing multi-year restrictions on their sale or transfer. As such, the exercise followed the sell-to-cover process, whereby a portion of the shares acquired through the exercise were sold in the open market, with the proceeds used to fund the aggregate exercise price of the options and the income and employment taxes associated with the exercise. The balance of the shares acquired through exercise that were delivered to the reporting person are subject to holding periods through the fifth anniversary of the date of this transaction. This stock option is exercisable in full. /s/Richard J. Nagel Jr. Attorney in fact for Claudio Tuozzolo 2021-09-15