One Wall Street skeptic on Facebook emerges

Mark Zuckerberg
David Paul Morris | Bloomberg | Getty Images

Most Wall Street analysts had glowing reviews of Facebook's earnings Thursday morning, except one.

Boutique research firm Monness Crespi Hardt downgraded the social network's stock to neutral from buy, telling investors to take profits due to a full valuation and rising costs related to video production.

Facebook's second quarter results blew away the consensus estimates on Wall Street and included some staggering figures, including mobile ad revenue growth of greater than 80 percent. More than 20 Wall Street analysts raised their price target on the stock after the earnings, according to FactSet data.

But not Monness analyst James Cakmak, who wrote to clients, "Despite the dominance of the platform, favorable secular trends, and emerging opportunities in new digital categories, we see diminishing upside to revenue prospects during our projection horizon."