Tuesday morning brought a big upward move to the stock market, largely in response to growing optimism about the reopening of the U.S. economy as fears about the coronavirus pandemic seem to be subsiding. The Nasdaq Composite (NASDAQINDEX:^IXIC) lagged somewhat behind broader market benchmarks, but it was still up 0.7% shortly before noon EDT. The Nasdaq 100 Index of larger Nasdaq-listed stocks was up a more modest 0.4%.

Many of the industries that have taken the biggest lumps during the coronavirus bear market were among today's best performers, and that was especially true among travel stocks. United Airlines Holdings (NASDAQ:UAL) led the way higher with a 13% gain, the biggest of any Nasdaq 100 stock Tuesday morning. Booking Holdings (NASDAQ:BKNG) managed a gain of 5%, with some smaller online travel portals seeing even larger gains on a percentage basis.

Flying the friendly skies

The gain in United and many of its airline peers would make many investors think that air travel had returned to normal. That's far from the case, and even as various parts of the country reopen their doors to business activity, the demand to go from place to place by air is likely to remain constrained for several months more.

United jet on the runway under a mostly cloudy sky.

Image source: United Airlines.

Even so, there have been some signs that things aren't as bad as airlines had feared. United recently decided that it would boost its scheduled capacity for July travel, and although that will still leave it 75% below where it was in July 2019, that's a big improvement from the 90% year-over-year cuts that United made for May and June air schedules.

United shares lost a huge portion of their value when the coronavirus pandemic began, and that leaves plenty of room for the stock to rebound if things get back to anything close to the precrisis normal. Value investors tend to be more averse to the big risk involved with turnaround plays of the magnitude of the airline industry, and there's still plenty of uncertainty in the space. Nevertheless, United has a lot to gain from renewed interest in air travel, and shareholders hope that the positive trends will continue.

Booking gains

The optimism in airline stocks also carried over to broader online travel portal companies. Booking Holdings picked up nearly 5%, while smaller players like Expedia Group (NASDAQ:EXPE) and TripAdvisor (NASDAQ:TRIP) weighed in with gains of 8% and 13%, respectively.

At first glance, it might seem like Booking is picking up steam for the same reasons as United and airline stocks. More people in the air means more people booking trips using Booking's website, especially for those who need hotel rooms once they reach their air travel destinations.

Yet some investors are concerned about online travel sites generally and Booking Holdings in particular. The stock has now recovered to within 20% of its previous high after having been down as much as 45%. That seems like a huge rebound given the continuing uncertainty surrounding the industry. Moreover, Booking was already seeing growth slow down even before the coronavirus crisis hit.

All that adds up to some nervousness about whether the gain in travel stocks is justified given what we're seeing in the industry. If things get back to normal, then the bounce seems warranted. But if there are lingering effects that change the way people travel -- as many believe there will be -- then the recent moves higher might prove overly optimistic.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.