A version of this story first appeared in CNN Business’ Before the Bell newsletter. Not a subscriber? You can sign up right here. You can listen to an audio version of the newsletter by clicking the same link.

London CNN Business  — 

The United States has officially flung open its doors to vaccinated international travelers. For companies in the industry, that’s reason to cheer.

What’s happening: Stocks in airlines have rallied this month in anticipation of the easing of restrictions, which investors hope will trigger a surge in bookings from people who haven’t been allowed to make the trip for roughly 20 months.

Shares of American Airlines (AAL) and Delta Air Lines (DAL) are up 14% and 13% in November, respectively, compared to a 2% rise for the S&P 500. European carriers such as British Airways owner IAG (ICAGY) and Air France-KLM (AFLYY) have also rallied.

Airlines across Europe reported full or nearly full flights to the United States on the first day of the relaxed restrictions.

The Lufthansa Group (DLAKY) told CNN Business that its carriers were operating 31 fully-booked flights to the United States on Monday. Virgin Atlantic said its flights were 98% full while both Swiss Air and British Airways said passenger volume on flights departing to US destinations was high.

The hope is that the move by the United States is part of a broader shift in international travel rules as countries take steps to live alongside Covid-19 instead of trying to eliminate transmission. Last month, Singapore — a major business travel hub — said it would ditch quarantine for fully vaccinated travelers from certain countries, as strict border controls loosen across Southeast Asia.

“International has picked up,” Expedia (EXPE) CEO Peter Kern told analysts after the company reported earnings last week.

Expedia’s revenue in its most recent quarter was up 97% compared to the same period last year. Its stock has jumped almost 11% this month.

Kern said that the pivot from the United States and Singapore provided an immediate boost.

“We see that lift up basically as soon as it’s announced,” he said. “We see search queries go up.”

But after an extremely volatile period, travel companies are hesitant to say the worst is behind them.

“As we look ahead, it’s clear that the recovery will continue to be choppy,” Delta CEO Ed Bastian said on the company’s recent earnings call.

Still, Bastian pointed to “clear underlying momentum,” thanks in part to the lifting of international travel rules. He said the US reopening to foreign tourists marked a “critical moment in our road to international recovery,” and predicted that 75% of Delta’s business would be restored by the end of 2021.

What could go wrong? New coronavirus variants that lead to a spike in infections remain a threat. Expedia noted that in the third quarter, the Delta variant led to a decline in reservations for lodging and air travel compared to the spring.

“We saw it impact cancellations,” Kern said. “We saw it impact booking trends.”

Rising fuel prices are also a problem for airlines. They could be forced to pass some of the higher costs on to customers, who may then think twice about purchasing expensive tickets.

Tesla shares plunge as Musk pledges to sell 10% of his stock

Tens of billions of dollars could be wiped off Tesla’s market value on Monday due to a Twitter poll.

The latest: Tesla (TSLA) CEO Elon Musk asked his followers over the weekend if he should sell 10% of his stock, a stake worth about $21 billion, my CNN Business colleague Walé Azeez reports.

“Much is made lately of unrealized gains being a means of tax avoidance, so I propose selling 10% of my Tesla stock,” he said. “Do you support this?”

The tweet appears to reference a Democratic proposal for billionaires to pay an annual tax on assets like stocks, bonds and real estate that have appreciated but haven’t been sold. Musk has criticized the plan.

With more than 3.5 million votes, 58% of respondents said “yes.”

“I was prepared to accept either outcome,” Musk followed up Sunday.

His exact plan for selling shares isn’t clear. But Tesla’s stock fell about 6% in premarket trading Monday.

Investor insight: Tesla’s stock has popped 73% this year, valuing the electric carmaker at $1.2 trillion. But trading remains choppy.

In the past year, shares have dropped at least 6% across seven trading sessions. They’ve jumped at least 6% across 13 trading sessions.

Watch this space: Musk has previously fallen foul of regulators for posting market-moving tweets without proper consultation.

In 2018, the US Securities and Exchange Commission charged him with fraud after Musk tweeted that he was considering taking Tesla private. He later secured a court-approved deal that required any social media posts containing information “material” to shareholders to be reviewed by the company first.

World food prices are up 30% in a year

Robust demand and lackluster harvests have driven world food prices to their highest level in more than a decade.

The United Nations recently reported that prices increased for the third consecutive month in October, rising 3% compared to September. The gains were driven by a sharp jump in vegetable oil and wheat prices.

The price of wheat surged 5% in October because of reduced harvests from major exporters including Canada, Russia and the United States.

And gains aren’t showing signs of easing. Earlier this month, December wheat futures hit their highest level since 2012.

Remember: The UN Food and Agriculture Organization Food Price Index has jumped by more than 30% over the past year.

In poorer countries with populations desperately in need of food assistance due to conflict or climate change, the increase risks amplifying pre-existing crises. David Beasley, the director of the United Nations’ World Food Programme, recently clashed with Tesla CEO Elon Musk after he said that giving $6 billion, or 2% of Musk’s net worth, could help solve world hunger.

Billionaires need to “step up now, on a one-time basis,” Beasley told CNN.

Rising food prices could also fan political discontent in richer countries, where elevated inflation expectations have been grabbing the attention of policymakers.

Up next

AMC Entertainment (AMC), PayPal (PYPL), Roblox, SmileDirectClub (SDC) and Virgin Galacti (SPCE)c report results after US markets close.

Coming tomorrow: Earnings from BioNTech (BNTX), Nio (NIO), Coinbase, DoorDash and Wynn Resorts (WYNN).

— Chris Liakos and Anna Cooban contributed reporting.