Analyst Downgrades Facebook Stock, Citing Price Run-up

Facebook CEO Mark Zuckerberg

"Too far, too fast," says Pivotal Research analyst Brian Wieser in a report about the recent gains of the social network's stock.

Facebook's stock has run up "too far, too fast," Pivotal Research Group analyst Brian Wieser said Thursday in downgrading his rating on the stock from "buy" to "hold."

He has a $48 price target on the stock, which had closed Wednesday's trading session at $50.28.

"We remain very positive on Facebook's underlying business," Wieser wrote in a report. "However, as the market increasingly appreciates Facebook's business, it is difficult to get excited about the stock from here."

He added: "More importantly, if investor expectations are above our revenue estimates (which are in line with consensus averages) investors are more likely to be disappointed than satisfied or surprised when third-quarter earnings is reported."

Wieser had launched his coverage of the stock with a rare "sell" rating before upgrading to a "hold" and eventually a "buy."

"In valuing a company's worth over extended periods of time -- and our price targets are set around year-end 2014 presently -- it is still important to make relative valuation calls on the company, especially when other companies implicitly offer similar returns for less risk or better returns for similar levels of risk," he emphasized in his Thursday downgrade note.

Facebook shares were down slightly in early afternoon trading.

Twitter: @georgszalai