Shares opened higher in Europe on Wednesday after gains in most Asian markets driven by hopes that a COVID-19 vaccine may hasten a return to normal for the global economy.

Benchmarks rose in Paris, London and Tokyo but slipped in Hong Kong and Shanghai. New Chinese regulations focused on technology companies pulled shares in big technology companies like Alibaba and Tencent sharply lower.

Markets have moderated after rallying earlier this week after Pfizer announced Monday that a potential COVID-19 vaccine it’s developing with German partner BioNTech may be 90% effective, based on early but incomplete test results. But experts have cautioned that many challenges remain, even if the shot is approved for use.

Meanwhile, investors are reassessing the high prices of Big Tech stocks that carried the stock market through the pandemic on expectations they’ll continue to thrive if the economy is in lockdown mode.

Britain’s FTSE 100 rose 0.2% to 6,310.92 and Germany's DAX edged 0.1% higher to 13,180.81. The CAC 40 in France also picked up 0.1%, to 5,425.84. Wall Street futures also saw modest gains, with the contract for the S&P 500 up 0.3 and the contract for the Dow trading 0.5% higher.

In Asia, Japan’s Nikkei 225 index gained 1.8% to 25,349.60 and the S&P/ASX 200 jumped 1.7% to 6,449.70. South Korea’s Kospi rose 1.4% to 2,485.87. India’s Sensex climbed 0.3% and shares in Taiwan also were higher.

Hong Kong's Hang Seng dropped back into negative territory, losing 0.3% to 26,226.98 while the Shanghai Composite slipped 0.5% to 3,342.20.

The proposed regulations issued Monday for public comment, typical of a global trend toward more oversight in the digital economy, give guidelines on how China’s 2008 anti-monopoly law will be applied to internet companies. The announcement gave no indication operators are accused of wrongdoing but cited areas where regulators might look for problems including sharing of information and alliances or pricing services below cost to keep out new competitors.

E-commerce giant Alibaba's shares plunged 9.8% in Hong Kong even as the company was in the midst of its annual Singles Day sales festival. Tencent, owner of the popular WeChat social media platform, sank 7.4% and online retailer JD.com tumbled 9.2%.

Overnight, the rising hopes for a COVID-19 vaccine pushed investors to reorder which stocks they see winning and losing.

The S&P 500 dipped 0.1% to 3,545.53. The Dow Jones Industrial Average gained 0.9% to 29,420.92 and the Nasdaq composite dropped 1.4%, to 11,553.86. The Russell 2000 index of small-cap stocks gained 1.9% to 1,737.01, finally returning to where it was in January and just 0.2% below its record high set in 2018.

Treasury yields and oil held onto their big gains from a day earlier or added some more amid strengthened confidence in the economy.

C learing uncertainty about U.S. leadership after Democrat Joe Biden clinched the last of the 270 electoral votes needed to become the next president has helped push the S&P 500 up 8.4% this month, even as some Republicans including Senate Majority Leader Mitch McConnell rally behind President Donald Trump’s efforts to fight the election results.

Many risks remain, the biggest perhaps whether investors have become too convinced about a potential COVID-19 vaccine just as c oronavirus counts surge at worrying rates across the U.S. and Europe, prompting some governments to restore restrictions on businesses.

“The biggest downside risk remains COVID and how severe this wave is going to be," Craig Erlam of Oanda said in a commentary. “COVID is impossible to ignore, particularly with cases soaring once again and deaths on the rise."

Republicans controlling the Senate on Tuesday unveiled a government-wide, $1.4 trillion spending bill to support the pandemic-ravaged economy. The mostly bipartisan measure faces uncertain odds amid the post-election tumult in Washington.

With fresh help for the U.S. economy from Congress still undecided, pressure is on central banks to step up support for markets.

“In fact, the end of this year could provide the perfect cocktail of widespread monetary and fiscal easing, combined with one or more vaccines," Erlam said.

Still, optimism remains across markets.

The yield on the 10-year Treasury was steady at 0.98%, close to its highest level since March.

Benchmark U.S. crude oil jumped $1.10 to $42.46 per barrel in electronic trading on the New York Mercantile Exchange. It rose 2.7% to settle at $41.36 per barrel on Tuesday. Brent crude, the international standard, picked up $1.10 to $44.71 per barrel.

In currency dealings, the dollar was rose to 105.46 Japanese yen from 105.31 yen. The euro weakened to $1.1793 from $1.1820.

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AP Business Writer Joe McDonald in Beijing contributed.