Delta stock is cheap, and investors should buy it now before prices go up, said senior analyst Brandon Oglenski.

Wall Street cheered on Thursday after Delta Air Lines, the second-largest U.S. air carrier, reported better-than-expected first-quarter earnings.

Still, some investors are passing on the stock because of rising costs and higher fuel prices.

"There's a lot of bears ... that say we do not want to own these stocks, there's a bad history here," Oglenski, director and senior equity analyst at Barclays Capital, told CNBC.

But, in general, he said, investors are "a bit too pessimistic on where this industry can ultimately shake out from a margin and returns perspective," Oglenski said Thursday on "Closing Bell."

While Oglenski admitted the stock has been volatile for the last few years, he remains bullish on Delta with an overweight rating.

"If you're an institutional holder of these stocks, trying to make money in an active portfolio, it's really challenging, and it feels like every forward step we make with revenue, initiatives on the commercial side, we take two steps back with fuel," Oglenski said.

But, he pointed out, "Wall Street is very fickle. We see fuel prices going up every day. That's the big wild card this year."

Thursday's record earnings included an adjusted operating revenue for the quarter of $9.76 billion, just under the $9.85 billion expected. The stock rose more than 3 percent during Thursday's session. At the end of trading Thursday, share prices for the airline hovered just under $53.