Airline stocks sank in Wednesday trading on United Continental's growth plan. Despite the declines, some strategists are still calling the group a buy ahead of a slew of other major airline earnings Thursday.



Airline stocks like Southwest, JetBlue and American Airlines were broadly weaker Wednesday, dragged down after United discussed its growth plans after its quarterly earnings report Tuesday evening, a report that did in fact beat estimates. The carrier's stock tumbled in after-hours trading. United shares fell more than 11 percent Wednesday.



Southwest, American Airlines, JetBlue and Alaska Air are all set to report Thursday before the opening bell; U.S. airlines are on track for their eighth straight year of profits in 2017. Delta reported quarterly earnings earlier this month, broadly beating Wall Street estimates.



"I think they're a big buy, because this is not your grandfather's airline," said Boris Schlossberg, managing director of foreign exchange strategy at BK Asset Management.



"The conventional wisdom now is that oil prices are high, so maybe airlines stocks are going to get hit, but I don't think that's the case anymore. They are such well-run machines at this point, they're basically IT businesses masquerading as transportation businesses," Schlossberg said Tuesday on CNBC's "Trading Nation."



He added that airlines have effectively figured out, "to the penny," how to control costs going forward. The one thing that could stand to handicap the airlines at this point, he said, is a decline in economic growth. After all, the NYSE Arca airline index has already advanced 2 percent in 2018, and 8 percent over the last three months.



"They're really enjoying generally macro growth right now, and if that slows down, that's the one threat to their business ... something they cannot control," Schlossberg said.



The airlines appear well-positioned here, said Max Wolff, chief economist at the Phoenix Group, after years of consolidation in the space.



"I still think these guys have a lot to worry about in terms of gas prices, the cost of being in debt," Wolff said Tuesday on "Trading Nation."



While Wolff said they appear to be a "pretty good play" for the next quarter or two, rising energy prices and interest rates are likely to weigh on the airlines.

American Airlines stock was down 6 percent Wednesday, while Southwest was off 4.8 percent and Delta declined 5.4 percent.