Futures tied to the S&P 500 climbed 1%, while contracts linked to the technology-laden Nasdaq Composite gained 1.3%. The Nasdaq last week suffered its biggest one-week decline since the market crisis of March.
Monday’s advance would extend a spell of outsize moves in both directions for global markets. Stocks have been buffeted by uncertainty about the U.S. presidential election, a slowing recovery in the world economy from the shock of Covid-19, and gyrations in tech shares that had driven markets higher since the spring.
“We’re shifting into an environment of lower returns and higher volatility and this is not inconsistent with that,” said James McCormick, global head of desk strategy at NatWest Markets.
“This isn’t a message that we’re going back to February, March markets,” Mr. McCormick added, referring to the historic declines that took place when countries locked down to control Covid-19. “But I think the upside is going be a bit capped here until we get through some of these events and risks.”
The Cboe Volatility Index, which estimates how far traders expect the S&P 500 to swing over the next month, ticked down to its lowest level since Sept. 3.
Investor sentiment was boosted by the resumption of clinical trials of AstraZeneca’s experimental coronavirus vaccine in the U.K., analysts said. Studies were put on pause globally after a person who received the vaccine had an unexplained illness. Trials in other countries, including the U.S., remain on hold.
“There’s a bit more positivity as regards vaccines,” said Robert Carnell, head of research for Asia-Pacific at ING Groep. “The resumption of AstraZeneca trials will be seen in that light.”
In the absence of bad news, Mr. Carnell added, “the default position [for stocks] is now to keep going up.”
There were some big moves in individual stocks ahead of the opening bell in New York after a busy weekend for mergers and acquisitions.
Shares of Oracle jumped around 8% after the tech company won the bidding for the U.S. operations of video-sharing app TikTok, according to people with knowledge of the matter. The deal may be structured as a partnership, rather than an acquisition, The Wall Street Journal reported.
Shares of Nvidia rose 5.6% after the chip maker neared a deal to buy British chip-designer Arm Holdings for more than $40 billion from SoftBank Group Corp. Shares in the Japanese technology conglomerate jumped 9%.
In government bonds, the yield on 10-year Treasury notes edged down to 0.662%, from 0.668% Friday. Traders are awaiting the conclusion of the Federal Reserve’s two-day monetary-policy meeting Wednesday, when the central bank is expected to hold interest rates steady.
The WSJ Dollar Index, which tracks the U.S. currency against a basket of others, slipped 0.1%.
U.S. crude-oil prices slipped 0.8% to $37.03 a barrel as traders awaited a monthly report on supply-and-demand by the Organization of the Petroleum Exporting Countries.
International stock markets were mixed. The Stoxx Europe 600 was down less than 0.1%, while China’s Shanghai Composite Index closed up 0.6% and Japan’s Nikkei 225 advanced 0.7%.
Write to Joe Wallace at Joe.Wallace@wsj.com