SunTrust Robinson analyst Bob Peck downgraded shares of Amazon.com, Inc. (NASDAQ: AMZN) to neutral from Buy on Monday arguing that the ‘near-term upside has been captured.'

Peck was on CNBC recently to elaborate on why he downgraded the stock.

Investors Becoming Euphoric

"The stock has done very well, it's almost 30 percent since their recent earning and of course 50 percent since that recent low this year, the stock has done very well," Peck said. "Whereas we talk to investors we found that investors were becoming almost euphoric on a couple of catalyst coming, particularly the AWS segment being broken out."

"We heard investors talking more about EBITDA multiples and revenue multiples and as you know [when] Amazon, it's a capital intensive business; you really need to focus on free cash flow."

He continued, "Catalyst for the call is Amazon in its 10-k broke out further information on capital leases and basically […]more cost and hence the free cash flow is lower and that multiple that investors think they are paying of about 40 times is something higher. We think [it's] close to 70 times the free cash flow."

Why Now?