X0306 4 2023-03-14 0 0001107843 QUALYS, INC. QLYS 0001558242 Thakar Sumedh S C/O QUALYS, INC. 919 E. HILLSDALE BLVD. FOSTER CITY CA 94404 1 1 0 0 CEO & President Common Stock 2023-03-14 4 M 0 511 23.51 A 179970 D Common Stock 2023-03-14 4 M 0 3789 30.58 A 183759 D Common Stock 2023-03-14 4 S 0 1908 118.9211 D 181851 D Common Stock 2023-03-14 4 S 0 2239 119.9511 D 179612 D Common Stock 2023-03-14 4 S 0 1666 120.641 D 177946 D Common Stock 2023-03-14 4 S 0 20 121.55 D 177926 D Stock Option (right to buy) 23.51 2023-03-14 4 M 0 511 23.51 D 2024-08-01 Common Stock 511 0 D Stock Option (right to buy) 30.58 2023-03-14 4 M 0 3789 30.58 D 2024-10-30 Common Stock 3789 43211 D The sale transaction reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on February 28, 2022. The sale price represents the weighted average price of the shares sold ranging from $118.34 to $119.32 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 $119.34 to $120.33 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 $120.34 to $121.20 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. This option is fully vested and immediately exercisable. /s/ Bruce Posey by power of attorney for Sumedh S. Thakar 2023-03-15