X0306 4 2016-01-01 0 0001410172 Rubicon Technology, Inc. RBCN 0001418016 Aquilano Don N C/O RUBICON TECHNOLOGY, INC. 900 EAST GREEN ST., UNIT A BENSENVILLE IL 60106 1 0 0 0 Common Stock 2016-01-01 4 A 0 200657 0.00 A 255488 D Consists of restricted stock pursuant to grants that vest according to the following schedule: 50,164 shares vest on March 31, 2016, 50,164 shares vest on June 30, 2016, 50,164 shares vest on September 30, 2016 and 50,165 shares vest on December 31, 2016. Includes 200,657 shares of restricted stock pursuant to grants that vest as indicated in footnote 1. /s/ Scott Glickson, Attorney-in-Fact for Don N. Aquilano 2016-01-05