Fortinet, Inc. — Director's Dealing 2016

May 3, 2016

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: FORTINET INC (FTNT)
CIK: 0001262039
Period of Report: 2016-04-29

Reporting Person: DEL MATTO ANDREW H (Chief Financial Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2016-04-29	Common Stock	S	4250	$31.8353	Disposed	14867	Direct
2016-05-01	Common Stock	M	7500	—	Acquired	22367	Direct
2016-05-01	Common Stock	M	1875	—	Acquired	24242	Direct
2016-05-01	Common Stock	F	4893	$32.51	Disposed	19349	Direct
2016-05-02	Common Stock	S	2000	$32.5249	Disposed	17349	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2016-05-01	Restricted Stock Units	$0	M	7500	Disposed		Common Stock (7500)	Direct
2016-05-01	Restricted Stock Units	$0	M	1875	Disposed		Common Stock (1875)	Direct

Footnotes

F1: The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 10, 2015.

F2: Represents the aggregate of sales effected on the same day at different prices.

F3: Represents the weighted average sales price per share. The shares sold at prices ranging from $31.37 to $32.30 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.

F4: Vesting of restricted stock units ("RSUs") granted to the Reporting Person on February 12, 2014.

F5: Vesting of RSUs granted to the Reporting Person on February 11, 2015.

F6: 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 on this row 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.

F7: The price per share was based on the fair market value of the Issuer's common stock on the vesting and release date, which, because such date was a Sunday, was the NASDAQ closing price on the last trading date immediately preceding the vesting and release date.

F8: Represents the weighted average sales price per share. The shares sold at prices ranging from $32.38 to $32.78 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.

F9: Each RSU represents a contingent right to receive one share of the Issuer's common stock.

F10: 25% of the RSUs vested on February 1, 2015, 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.

F11: 25% of the RSUs vest on February 1, 2016, 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.