‘You can’t bet against’ Amazon: Pro

Forget traditional valuation metrics when evaluating a stock such as Amazon.com, Rosecliff Captial's Mike Murphy said Friday.

"You can't bet against this name," he said. "I think making the valuation argument, you just really have to throw it out the window."

On CNBC's "Fast Money," Murphy said that he had bought into the valuation argument when he shorted the stock months ago and covered it to cut his losses.

"The stock's up here at $309. You can't keep making that argument,"he added. "I think what Jeff Bezos is doing is incredible."

(Read more: Amazon.com stock still worth owning, pro says)

OptionMonster's Jon Najarian noted that Amazon had challenged large players in the technology sector with their cloud-computing Amazon Web Services business.

"This is huge for these guys, and they're crushing it against big competitors, like Microsoft and Google," he said. "Unless they make a significant misstep, people will continue to bet on them going forward."

Citigroup internet analyst Mark May called Amazon.com one of the only web-based companies that "remained revelant and on top of its game."

(Read more: Pro sees 'massive' opportunity for Facebook stock)

"And the way it's been doing that is a consistent push to innovate and invest," he added. "It's a growth company, so really what we're focused on this company first and foremost is top-line growth."

May said that the company should be evaluated on potential long-term returns on its digital media and fast-growing web-services businesses.

May's had a "buy" rating on the stock and a $340 price target.

(Read more: Top strategist's earnings scorecard—so far)

He also had "buy" ratings on Google, with a price target of $1,100 per share, and on Yahoo, with a price target of $30. May was "neutral" on Facebook with a $32 price target.

By CNBC's Bruno J. Navarro. Follow him on Twitter @Bruno_J_Navarro.

Trader disclosure: On July 26, 2013, the following stocks and commodities mentioned or intended to be mentioned on CNBC's "Fast Money" were owned by the "Fast Money" traders: Steve Weiss is long C; Steve Weiss is short UCP; Steve Weiss is long WLH; Steve Weiss is short TMHC; Steve Weiss is short CAT; Pete Najarian is long AAPL; Pete Najarian is long BAC; Pete Najarian is long C; Pete Najarian is long YHOO; Pete Najarian is long SBUX; Pete Najarian is long NFLX; Pete Najarian is long FB; Pete Najarian is long BBRY ; Pete Najarian is long MSFT; Pete Najarian is long BX; Mike Murphy is long BAC; Mike Murphy is long C; Mike Murphy is long LEN; Mike Murphy is long TOL; Jon Najarian is long TSLA; Jon Najarian is long AMZN ; Jon Najarian is long ZNGA; Jon Najarian is long EBAY; Jon Najarian is long QCOM; Jon Najarian is long NTAP; Jon Najarian is long EMC; Jon Najarian is long VMW; Jon Najarian is sold EXPE puts.