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."