The S&P 500 opened higher by 68.68 points, or 2.40%, at 2,932.38 after the open. The Nasdaq Composite gained 162.59 points, or 1.80%, to 9,177.15.
Investors have kept a close eye on the vaccine programs of several drugmakers, cheering any positive development amid fears of a second wave of infections as governments start easing restrictions.
Drugmaker Moderna Inc said its experimental vaccine for COVID-19 showed promising results in an early stage study. The stock jumped 26% in premarket trade.
Markets were also encouraged by Federal Reserve Chairman Jerome Powell's remarks over the weekend on a gradual economic recovery, and his affirmation that more monetary stimulus was on the way if required.
Wall Street's three major indexes closed higher on Friday as investors weighed worries about Sino-US trade relations and weaker-than-expected US economic data against growing optimism that easing coronavirus restrictions would boost activity this month.
However, they posted a weekly loss as uncertainty still persisted over how the world would emerge from the coronavirus. US stock indexes have stuck to a tight range after recovering from multi-year lows hit in March.
Cruise line operators Carnival Corp, Royal Caribbean Cruises Ltd, Norwegian Cruise Line Holdings Ltd jumped more than 7% as well as carriers like Delta Air Lines Inc and United Airlines Holdings gained more than 7% and 8.4%.
General Motors Co rose 5.2% and Ford Motor Co 4% as they prepared to reopen their North American factories in a push to restart work in an industry that accounts for about 6% of US economic activity.
Oil and gas heavyweights Occidental Petroleum Corp, Halliburton Co, Schlumberger jumped between 5.5% and 5.8% after oil prices surged on the prospect of higher demand.
Apple Inc rose 1.9% as the iPhone maker said it would reopen more than 25 of its branded stores in the United States this week.