AMC (AMC) and other entertainment stocks surged on Monday in the wake of Pfizer (PFE) and BioNTech (BNTX) announcing positive news about their leading COVID-19 vaccine candidate, which demonstrated a high level of efficacy in testing.

Even as the U.S. topped 10 million coronavirus cases, markets — which for months have been pricing in hopes of an end to the crisis — skyrocketed on the news. The Dow (^DJI) and S&P 500 (^GSPC) both opened at record highs, tempering those gains slightly by midday but still up sharply on the day.

Pfizer plans to apply for emergency use authorization of the vaccine at the end of this month, fueling hopes that people will venture out to theaters and entertainment venues, and start traveling again.

“With the vaccine news today, households and firms are going to plan ahead, for example by booking travel, vacation, and [capital expenditures],” noted Torsten Slok, chief economist at Apollo Global Management. He noted that in total, some 27 million workers, or nearly 22% of the U.S. workforce, are in occupations that require close physical contact to clients.

With Pfizer aiming to have over 1 billion doses ready by next year, “the implication is that we will immediately begin to see the positive effects on employment, GDP, and earnings, even before the vaccine is available to the public,” Slok added.

AMC was trading up more than 50% by mid-session, after opening around 70% higher. Cineworld (CINE.L) and Cinemark (CNK) each also gained more 30%. Theaters have been hard hit by the pandemic as people have stayed at home, despite limited capacity re-opening measures across many states, and major studios have mostly postponed big tentpole productions.

Travel stocks also saw double digit percentage spikes on Monday. American Airlines (AAL), United (UAL), and Delta (DAL) all soared by double digits in midday trading. Those moves overshadowed a dramatic selloff in major beneficiaries of the “stay-at-home” stocks like Zoom (ZM), Amazon (AMZN), Netflix (NFLX) and Peloton (PTON), all of which have outperformed during the pandemic.

However, some analysts warned about the potential for investors to overreact to Pfizer’s announcement — cautioning against “knee-jerk reactions” that eventually get confronted by reality.

“You’ve seen a huge reaction this morning in the airlines, but again, that doesn’t mean tomorrow everyone is booking trips,” Victoria Fernandez, chief market strategist at Crossmark Global Investments, told Yahoo Finance Live.

“They don’t have the vaccine yet, there’s limited quantities of that to go around. We know that this is probably going to be a late 2021 story when people are actually able to get the vaccines,” she warned.

Fernandez says valuations on companies moving on vaccine news shouldn’t be changing overnight. She warns investors to be careful of chasing the market because there may be “whip-saw” action and volatility ahead.

“I think COVID-19 is still an uncertainty right now. Yes we have positive news on the vaccine but that doesn’t mean long term everything is going to be perfect,” said Fernandez.

Ines covers the U.S. stock market. Follow her on Twitter at @ines_ferre

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