NEW YORK (

TheStreet

) --

Fortinet

(FTNT) - Get Report

shares tumbled 5.22% to $24.50 before market open following

Yahoo!'s

(YHOO)

announcement that it has

hired

the security specialist's finance chief, Ken Goldman, to be its new chief financial officer.

In a statement released after market close on Tuesday, the Internet giant said that Goldman will assume the CFO role at Yahoo! on Oct. 22, reporting directly to CEO Marissa Mayer.

Yahoo!'s current Chief Financial Officer Tim Morse will leave the company later this fall, according to the statement.

Shares of the Sunnyvale, Calif.-based company crept up 0.22% to $15.71 on Wednesday.

Research In Motion

(RIMM)

shares gained 1.97% to reach $6.73, a day after the company showed off a

beta version

of its next-generation BlackBerry smartphone.

The embattled Canadian handset maker, which reports its second-quarter results after market close on Thursday, was also one of the most active premarket Nasdaq stocks on share volume of 118,942.

Facebook

(FB) - Get Report

shares dipped 0.89% to $20.10 on share volume of 129,154.

Satellite radio specialist

Sirius XM

(SIRI) - Get Report

was another active premarket stock, slipping 0.2% to $2.47 on share volume of 70,899.

--Written by James Rogers in New York.

Follow @jamesjrogers

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