Investors are overlooking Facebook's potential at their own peril, Leon Cooperman of Omega Advisors said Thursday on CNBC.
"We think that people are underestimating the mobility opportunity that exists in Facebook," he said. "We think ultimately they could achieve a market cap comparable to a Google, which would make the stock very, very rewarding."
Cooperman made headlines in February when he announced that he had exited his position in Apple stock and bought shares of Facebook.
On "Fast Money," Cooperman, who calls himself a value investor, acknowledged that Facebook's valuation might appear rich.
"A little more speculative, a higher multiple than the kind of things we're normally involved in, but we think there's a lot of wind to their back," he said.
(Read More: Leon Cooperman's Winning Apple Stock Play)
Cooperman also said that he thought Facebook's increased performance from advertising and mobile would be reflected in stock price.
"We think that's coming," he said. "The numbers are starting to ramp up."
Facebook's market cap stood around $48 billion, while Google clocked in at $237 billion.
Shares of Facebook, which were lower in morning trading, crossed into positive territory after Cooperman's comments. It traded $27.34 per share at 1:18 ET.