X0306 4 2021-11-01 0 0001262039 Fortinet, Inc. FTNT 0001475586 Xie Michael C/O FORTINET, INC. 899 KIFER ROAD SUNNYVALE CA 94086 1 1 0 0 VP, Engineering & CTO Common Stock 2021-11-01 4 M 0 1775 0.00 A 5951800 D Common Stock 2021-11-01 4 M 0 1352 0.00 A 5953152 D Common Stock 2021-11-01 4 M 0 1018 0.00 A 5954170 D Common Stock 2021-11-01 4 F 0 2057 324.11 D 5952113 D Common Stock 2021-11-02 4 S 0 337 325.9205 D 5951776 D Common Stock 2021-11-02 4 S 0 500 326.928 D 5951276 D Common Stock 2021-11-02 4 S 0 851 327.9855 D 5950425 D Common Stock 2021-11-02 4 S 0 200 329.43 D 5950225 D Common Stock 2021-11-02 4 S 0 200 330.72 D 5950025 D Common Stock 3408214 I See footnote Common Stock 1991686 I See footnote Restricted Stock Units 0.00 2020-11-01 4 M 0 1775 0.00 D Common Stock 1775 1775 D Restricted Stock Units 0.00 2020-11-01 4 M 0 1352 0.00 D Common Stock 1352 6756 D Restricted Stock Units 0.00 2021-11-01 4 M 0 1018 0.00 D Common Stock 1018 9166 D Vesting of restricted stock units ("RSUs") previously granted to the Reporting Person. Exempt transaction pursuant to Section 16b-3(e) - payment of exercise price or tax liability by delivering or withholding securities incident to the receipt, exercise or vesting of a security issued in accordance with Rule 16b-3. All of the shares reported as disposed of in this Form 4 were relinquished by the Reporting Person and cancelled by the Issuer in exchange for the Issuer's agreement to pay federal and state tax withholding obligations of the Reporting Person resulting from the vesting of RSUs. This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person. Represents the weighted average sale price. The lowest price at which shares were sold was $325.54 and the highest price at which shares were sold was $326.34. The Reporting Person undertakes to provide upon request to the staff of the Securities and Exchange Commission, the Issuer or its stockholders, full information regarding the total number of shares sold at each separate price within the ranges set forth in footnotes (4), (5), (6), (7) and (8) to this Form 4. Represents the weighted average sale price. The lowest price at which shares were sold was $326.928 and the highest price at which shares were sold was $326.56. Represents the weighted average sale price. The lowest price at which shares were sold was $327.56 and the highest price at which shares were sold was $328.45. Represents the weighted average sale price. The lowest price at which shares were sold was $329.06 and the highest price at which shares were sold was $329.80. Represents the weighted average sale price. The lowest price at which shares were sold was $330.56 and the highest price at which shares were sold was $330.88. Shares held directly by The K.A. Children's Trust dated February 9, 2011, for which the Reporting Person serves as a trustee. Shares held directly by the 2010 K.A. Family Trust dated May 3, 2010, for which the Reporting Person serves as a trustee. Each RSU represents a contingent right to receive one share of the Issuer's common stock upon vesting. 25% of the RSUs vested on February 1, 2019, then the remaining 75% of the RSUs vest in equal installments on each quarterly anniversary thereafter until 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. RSUs do not expire; they either vest or are canceled prior to vesting date. 25% of the RSUs vested on February 1, 2020, then the remaining 75% of the RSUs vest in equal installments on each quarterly anniversary thereafter until 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. 25% of the RSUs vested on February 1, 2021, then the remaining 75% of the RSUs vest in equal installments on each quarterly anniversary thereafter until 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. /s/ Robert Turner, by power of attorney 2021-11-03