X0306 4 2017-11-15 0 0001107843 QUALYS, INC. QLYS 0001045434 DIXON DONALD R 505 HAMILTON AVENUE SUITE 200 PALO ALTO CA 94301 1 0 0 0 Common Stock 2017-11-15 4 S 0 7707 57.8047 D 196839 D Common Stock 2017-11-15 4 S 0 49 57.8041 D 1234 I See Footnote Common Stock 2017-11-15 4 S 0 6374 57.8047 D 158700 I See Footnote Common Stock 2017-11-16 4 S 0 25437 58.0858 D 171402 D Common Stock 2017-11-16 4 S 0 9202 58.6095 D 162200 D Common Stock 2017-11-16 4 S 0 271 57.9262 D 963 I See Footnote Common Stock 2017-11-16 4 S 0 25100 58.0723 D 133600 I See Footnote Common Stock 2017-11-16 4 S 0 9603 58.6008 D 123997 I See Footnote The sale price represents the weighted average price of the shares sold ranging from $57.05 to $57.75 per share. Upon request by the Commission staff, the Issuer or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4. The sale price represents the weighted average price of the shares sold ranging from $57.50 to $57.55 per share. Upon request by the Commission staff, the Issuer or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4. The shares are held directly by Dixon Family Trust U/A Dated 6/18/88, for which the Reporting Person and his spouse serve as settlors. /s/ Bruce Posey by power of attorney 2017-11-17