X0306 4 2017-02-15 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 2017-02-15 4 S 0 760 37.6848 D 9368 D Restricted Stock Units 0 2017-02-16 4 A 0 30000 0 A Common Stock 30000 30000 D Nonqualified Stock Option (right to buy) 37.24 2017-02-16 4 A 0 30000 0 A 2024-02-16 Common Stock 30000 30000 D The sales reported on this Form 4 were effected pursuant to Rule 10b5-1 trading plans adopted by the Reporting Person on 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 February 14, 2017. Represents the weighted average sales price per share. The shares sold at prices ranging from $37.64 to $37.72 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. Each restricted stock unit ("RSU") represents a contingent right to receive one share of the Issuer's common stock. 25% of the RSUs vest on February 1, 2018, then the remaining 75% of the RSUs vest in equal installments on each quarterly anniversary thereafter, until such time as the RSUs are 100% vested, subject to the continuing employment of the Reporting Person on each vesting date. Shares of the Issuer's common stock will be delivered to the Reporting Person upon vesting. 1/4 of the shares subject to the option vest on February 16, 2018 and 1/48 of the shares subject to the option vest monthly thereafter. /s/ John Whittle 2017-02-17