By Anna Isaac

U.S. stock futures edged higher Monday as investors cheered signs that political uncertainty may ebb following reports of President Trump's improving health condition, while former Vice President Joe Biden's rising lead in the polls suggested a more decisive outcome in the elections.

Futures tied to the S&P 500 rose 0.7%, signaling that the broad market gauge may recover some ground after the New York opening bell. Contracts linked to the Nasdaq-100 climbed 0.9%.

Uncertainty had rattled markets Friday after Mr. Trump tested positive for Covid-19, raising questions about the functioning of the government, the election campaign and the Supreme Court nomination process if the president were to be sidelined.

Equities remain sensitive to any signals about the state of Mr. Trump's health, investors said. Doctors said the president's condition was improving on Sunday, though they also noted that his blood oxygen level had dropped twice and that he was taking a steroid typically given to Covid-19 patients who are seriously ill. His medical team has said he could be sent back to the White House as soon as Monday, following several days of contradictory information from doctors and advisers.

The upbeat assessment has "helped risk appetite, but I would be more skeptical," said Jane Foley, head of foreign-exchange strategy at Rabobank. "There's been a little confusion about what doctors have said, and to-ing and fro-ing about his condition."

Mr. Biden's lead over the president also appears to have widened, according to a poll conducted by The Wall Street Journal and NBC News in the two days following the debate. That signals there may be less room for dispute over the results of the November elections, which would be welcomed by markets. But the views were sought before news emerged that Mr. Trump had tested positive for Covid-19.

"As people get their head around the idea that Biden is set to be president and the Democrats could sweep Congress, they're realizing the impact on the stock market will be pretty large given a likely bigger fiscal stimulus," said James McCormick, a strategist at NatWest Markets.

In recent weeks, markets have grown increasingly skeptical that Democrats and the White House will reach an agreement over the size and terms of the government's next coronavirus-relief spending package. Many investors are instead trying to assess what Mr. Biden's electoral victory might mean for the fiscal package and for issues such as corporate taxes.

"People are starting to question whether or not a Biden win would be an outright negative for equities," Mr. McCormick said. "There are tax implications, but there are also some positive stimulus implications."

Political uncertainty has led to choppy trading in recent days, and there are signs that the market turbulence will continue. The Cboe Volatility Index, an options-based gauge of investors' expectations for market swings, is near its highest level in almost a month.

Regeneron Pharmaceuticals shares rose nearly 5% ahead of the opening bell in New York after the White House said Friday the president received an eight-gram dose of Regeneron's antibody drug cocktail as a precautionary measure.

Shares in Cineworld Group, which owns Regal Entertainment Group, plummeted nearly 40% in London after the second-largest cinema chain in the U.S. said it was closing all of its locations nationwide, after reopening in August, escalating the pandemic-driven crisis facing the entertainment industry.

In bond markets, the yield on the benchmark 10-year U.S. Treasury ticked higher to 0.710%, from 0.694% Friday.

In commodities, Brent crude, the international energy benchmark, rose 3.7% to $40.74 a barrel. Gold edged down 0.2%.

Overseas, the pan-continental Stoxx Europe 600 rose 0.7%.

Major Asian stock markets also rallied by the close of trading. Japan's Nikkei 225 rose 1.2%. Hong Kong's Hang Seng Index advanced 1.3%. China's Shanghai Composite Index remained closed for a holiday.

The Institute for Supply Management's survey of purchasing managers in the service sector, due out at 10 a.m. ET, is expected to show another expansion in U.S. activity last month as businesses reopened.

Write to Anna Isaac at anna.isaac@wsj.com

(END) Dow Jones Newswires

10-05-20 0750ET