U.S. stocks are broadly higher in afternoon trading Wednesday as the effort to develop and distribute vaccines to fight the virus pandemic ramps up.

The gains put the market back on positive footing following a modest pullback on Tuesday. Britain has authorized the use of a COVID-19 vaccine developed by AstraZeneca and Oxford University. The vaccine is considered easier to store and handle than others hitting the market. Earlier in December, both the U.K. and U.S. approved a vaccine made by Pfizer.

Meanwhile, vaccine development continues around the globe, with China’s Sinopharm becoming the latest to release encouraging study results.

The S&P 500 was up 0.3% as of 1:05 p.m. Eastern and hovering around a record high set on Monday. Technology companies, banks and industrial stocks are leading the way, though the gains are broad. Roughly 80% of stocks in the index rose.

The Dow Jones Industrial Average rose 159 points, or 0.5%, to 30,495. The Nasdaq composite was up 0.3%.

Small-company stocks again outpaced their larger rivals as the Russell 2000 gained 1.2%. That’s a sign that investors are feeling more optimistic about the economy.

Stocks have been mostly grinding higher in recent weeks, with indexes setting new highs, amid optimism that coronavirus vaccinations will pave the way in coming months for the economy to escape from the pandemic’s grip. With one day of trading left in 2020, the S&P 500 is up 15.7% this year, while the Nasdaq is up 43.7%.

Investors are optimistic about more vaccines gaining approval and reaching the market in coming weeks, though the potential for logistics problems remains, said Ryan Detrick, chief market strategist for LPL Financial.

“The hiccups are the actual rollout,” he said. “Approving them is one thing, but getting them out and into people’s arms is another thing.”

Treasury yields were mixed. The yield on the 10-year Treasury held steady at 0.93%.

Stock markets in Europe were down after European Union officials and British lawmakers approved a separation deal that will govern trade and other relations after the year ends. The U.K. left the EU almost a year ago, but remained within the bloc’s economic embrace during a transition period that ends this year.

Britain’s FTSE 100 fell 0.7% and Germany’s DAX slipped 0.3%. The CAC 40 in Paris dropped 0.2%.

Markets in Asia closed mostly higher, though Japan’s Nikkei fell 0.5% as the Tokyo exchange marked the end of trading for the year.

Traders in cryptocurrencies continued to push up the price of bitcoin, which has more than doubled the past three months. It was up 6.3% to $28,255, according to the tracking site CoinDesk. Bitcoin futures on the Chicago Mercantile Exchange were up 5.2% to $28,630. The futures allow investors to make bets on the future price of the digital currency.

Trading volume on Wall Street has been thin in the final week of 2020. The market will be closed for New Year’s Day Friday.