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Table of Contents ( Mark One ) UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 10 - K ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the year ended December 31 , 2020 TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from or Delaware ( State or other jurisdiction of incorporation or organization ) FORTINET , INC . ( Exact name of registrant as specified in its charter ) to Commission file number : 001-34511 Common Stock , $ 0.001 Par Value ( Title of each class ) 899 Kifer Road Sunnyvale , California 94086 ( Address of principal executive offices , including zip code ) ( 408 ) 235-7700 ( Registrant's telephone number , including area code ) 77-0560389 ( I.R.S. Employer Identification No. ) Securities registered pursuant to Section 12 ( b ) of the Act : FTNT The Nasdaq Stock Market LLC ( Name of exchange on which registered ) ( Trading Symbol ) Securities registered pursuant to Section 12 ( g ) of the Act : None No □ Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes > Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Act . Yes No