After 78 days in darkness, the Las Vegas strip is breathing new life.

Led by the reopening of casinos held by Wynn Resorts, Caesars Entertainment, MGM Resorts and Las Vegas Sands, Thursday marked a return to operations at many of Sin City’s most frequented attractions. Even MGM’s famed Bellagio’s fountains were roaring again to the tune of Elvis’ Viva Las Vegas.

But as the coronavirus pandemic threat continues, analysts are warning that a total return to normalcy for gaming stocks might not be as quick as hoped. Despite a slow trickle back to booking activity, Morningstar senior equity analyst Dan Wasiolek estimates it could take until 2023 before Las Vegas revenues return to pre-COVID-19 levels.

“Looking at the short-term, I think there will be some initial pent-up demand,” Wasiolek told Yahoo Finance’s YFi PM. “That being said I think getting back to 2019 levels might take three or four years ... and that really harmonizes with what we’ve seen in past demand shocks such as 9/11 and the Great Financial Crisis.”

That measured guidance hasn’t stopped a reopening rally this week that has boosted Wynn and MGM shares higher by about 15% to start the month. Off their March lows, shares have rallied some 120% and 200%, respectively.

Whether that momentum continues could hinge on whether bookings, which Wasiolek says are still off about 80% in the quarter, continue to recover. So far, pricing has indicated a weak position of strength for a lot of the Vegas properties hopeful to draw back guests, according to Brian Egger, an analyst with Bloomberg Intelligence. With gaming floors operating at about 50% capacity, events yet to come back, and clubs remaining closed for at least the first phase of reopening, revenue streams aren’t going to be as diverse as before.

“When you’re talking about Las Vegas, you’re probably talking about 50% of the revenue coming from traditional gaming activities including tables and slots, the remainder coming from restaurants and other non-gaming amenities,” explains Moody’s senior vice president Keith Foley. “If you’re operating at about 50% capacity of slots ... I would expect revenues are not going to be near the 50% of what a casino normally gets, I would expect it to be well below that.”

To be fair, some of the gaming leaders have come to rely less and less on Las Vegas as growth has taken off in China’s Macau region. As Foley notes for both Wynn and Las Vegas Sands, the bulk of both company’s revenue now comes from Macau. For example, Las Vegas only accounted for about 25% of Wynn’s 2019 EBITDA, while only accounting for about 10% of Las Vegas Sands’ business.

Despite the longer road expected ahead of the gaming giants, Morningstar’s Wasiolek notes that Wynn, MGM, and Las Vegas Sands still trade below what he considers fair market value.

“There is an opportunity here if you’re a long-term oriented investor, even though the stocks have moved off the bottoms,” he said. At a price target for Wynn shares at $122, Wasiolek measures about a 22% upside potential compared to the 20% upside estimated for Las Vegas Sands.

“Looking from a longer-term aspect when you look at travel and gaming these are areas that have fully recovered and we expect that to be the case again during this demand shock,” he said.

Zack Guzman is the host of YFi PM as well as a senior writer and on-air reporter covering entrepreneurship, cannabis, startups, and breaking news at Yahoo Finance. Follow him on Twitter @zGuz.

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