He said he upgraded the stock right before the quarter in anticipation of Amazon's unveiling of the sales figures for its Web services sector. He has a "buy" rating on the stock and a $450 price target.
"This is the first time we felt that we had a catalytic event by peeling the onion back and seeing what their Amazon web services was doing," Cakmak said.
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In its earnings release after the bell Thursday, the ecommerce giant called the Web services sector a $5 billion business. Amazon also beat revenue expectations and its quarterly loss was in line with Street estimates. The stock rallied after hours Thursday and was trading higher Friday.
Amazon is also the top pick of Jason Helfstein, managing director of Internet equity research for Oppenheimer. He has an "outperform" rating on the stock, with a $415 price target.
"If you dug into the web services business even a year ago, you could tell by talking to competitors that Amazon was a real player," he told "Power Lunch."
Amazon is up about 43 percent year to date. Cakmak said "you can make a very solid argument there that it deserves a premium multiple" because of the combination of the company's core business and its web services business.
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As for the other three horsemen, their stock performances vary. Apple is up over 17 percent, while Google is up 8 percent and Microsoft is up over 3 percent.
Oppenheimer has "outperform" ratings on Apple and Microsoft, with a $155 price target and $50 price target respectively. It has a "perform" rating on Google and a $550 price target.
Monness, Crespi, Hardt & Co. has a "buy" rating on Apple, with a $145 price target, and a "neutral" rating on Google. The firm does not cover Microsoft.
—CNBC's Jackie O'Sullivan and Karma Allen contributed to this report
Disclosures: Oppenheimer owns shares of AMZN, GOOGL, Helfstein does not. Cakmak and his firm do not own AMZN, GOOGL.