X0609 4 2026-06-03 0001262039 Fortinet, Inc. FTNT 0001475586 Xie Michael false C/O FORTINET, INC. 909 KIFER ROAD SUNNYVALE CA 94086 true true false false VP, ENGINEERING & CTO 1 Common Stock 2026-06-03 4 S 0 464 144.458 D 9927053 D Common Stock 2026-06-03 4 S 0 410 145.7184 D 9926643 D Common Stock 2026-06-03 4 S 0 2337 146.5502 D 9924306 D Common Stock 2026-06-03 4 S 0 564 147.7076 D 9923742 D Common Stock 2026-06-03 4 S 0 132 148.3009 D 9923610 D Common Stock 25680202 I By trust Common Stock 5513505 I See footnote Common Stock 5513505 I See footnote Common Stock 4646144 I By trust Common Stock 4646144 I By trust The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 4, 2026. Represents the weighted average sale price. The lowest price at which shares were sold was $144.03 and the highest price at which shares were sold was $144.64. 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 (2) through (6) to this Form 4. Represents the weighted average sale price. The lowest price at which shares were sold was $145.10 and the highest price at which shares were sold was $146.07. Represents the weighted average sale price. The lowest price at which shares were sold was $146.14 and the highest price at which shares were sold was $147.03. Represents the weighted average sale price. The lowest price at which shares were sold was $147.23 and the highest price at which shares were sold was $147.99. Represents the weighted average sale price. The lowest price at which shares were sold was $148.28 and the highest price at which shares were sold was $148.31. These securities are held by the 2010 K.A. Family Trust dated May 3, 2010, for which the Reporting Person serves as a trustee. Shares held directly by the KAXX Trust under The K.A. Children's Trust dated February 9, 2011, for which the Reporting Person serves as a trustee. Shares held directly by the KAJJ Trust under The K.A. Children's Trust dated February 9, 2011, for which the Reporting Person serves as a trustee. These securities are held by a grantor retained annuity trust for the benefit of the Reporting Person. These securities are held by a grantor retained annuity trust for the benefit of the Reporting Person's spouse. /s/ Robert Turner, by power of attorney 2026-06-03