Facebook earnings just the start: Pro

Facebook's better-than-expected quarterly earnings sent share higher in after-hours trading, but there's a larger case for stock appreciation, Jordan Rohan of Stifel Nicolaus said Wednesday.

"I do think this is still one of the under-owned and underestimated stocks out there," he said, adding that portfolio managers were "all crowded into Google stock."

Facebook stock closed at $26.51, up 0.38 percent. After the social media company released quarterly results, the stock jumped more than 18 percent to trade around $31.38 at 5:39 p.m. ET.

On CNBC's "Fast Money," Rohan said that the stock was still a "buy."

(Read more: Facebook lacks leadership, Porter Bibb says)

"Now you have an opportunity here to buy Facebook at a valuation that's still compelling, and numbers are head up significantly higher," he added.

Rohan had a $29 price target for shares on Facebook but didn't increase it after it was topped.

"There's no news-breaking on TV for stock analysts," he said, adding that he would review his analysis.

But there was another big potential catalyst ahead for Facebook stock.

(Read more: What Apple needs to be a $500 stock)

"I don't get the sense that any of the portfolio manager, who will have to own Facebook if it's added to the S&P 500, I don't get a sense anybody's full-up on Facebook yet," he said.

"This is a name that's going to be elevated once again to premium internet company," Rohan added. "Whether it stays there forever, I'll deal with that in time. But in the near-term, I think that's what's going to happen."

— By CNBC's Bruno J. Navarro. Follow him on Twitter @Bruno_J_Navarro. CNBC's Michael Newberg contributed research to this report.

Trader disclosure: On July 24, 2013, the following stocks and commodities mentioned or intended to be mentioned on CNBC's "Fast Money" were owned by the "Fast Money" traders: Karen Finerman is long AAPL; Karen Finerman is long BAC; Karen Finerman is long C; Karen Finerman is long JPM; Karen Finerman is long GOOG; Karen Finerman is long M; Karen Finerman is long TGT; Karen Finerman is long OCR; Karen Finerman is long MDY PUTS ; Dan Nathan is short BBRY 12/10 put spread; Dan Nathan is long BA Aug 9 put fly ; Dan Nathan is long TXN Aug 38/36 put spread; Guy Adami is long C; Guy Adami is long GS; Guy Adami is long INTC; Guy Adami is long MSFT; Guy Adami is long AGU; Guy Adami is long NUE; Guy Adami is long BTU; Guy Adami's wife, Linda Snow, works at Merck; Jon Najarian is long AAPL; Jon Najarian is long SBUX ; Jon Najarian is long CSCO; Jon Najarian is long FB; Jon Najarian is long EBAY; Jon Najarian is long QCOM; Jon Najarian is long EMC; Jon Najarian is long VMW; Jon Najarian is long NTAP; Jordan Rohan is long FB.