X0306 4 2016-08-15 0 0001262039 FORTINET INC FTNT 0001476336 Whittle John C/O FORTINET, INC. 899 KIFER ROAD SUNNYVALE CA 94086 0 1 0 0 VP CorpDev&Strat Alliance, GC Common Stock 2016-08-15 4 S 0 983 32.8627 D 17531 D Common Stock 2016-08-16 4 S 0 12850 35.00 D 4681 D The sales reported on this Form 4 were effected pursuant to Rule 10b5-1 trading plans adopted by the Reporting Person on February 24, 2015 and February 12, 2016. Represents the aggregate of sales effected on the same day at different prices. These shares were previously acquired by the Reporting Person under the Issuer's employee stock purchase plan on August 12, 2016. Represents the weighted average sales price per share. The shares sold at prices ranging from $32.85 to $32.88 per share. Full information regarding the number of shares sold at each price shall be provided upon request to the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer. /s/ John Whittle 2016-08-17