Wall Street stocks ended at fresh records on Thursday, a buoyant start to the 2020 trading campaign that extended the late-2019 rally.
The Dow Jones Industrial Average advanced 1.2 percent to 28,868.80.
The broad-based S&P 500 gained 0.8 percent to 3,257.85, while the tech-rich Nasdaq Composite Index jumped 1.3 percent to 9,092.19, its biggest single-session gain in nearly three months.
All three indices finished at all-time highs, the latest in a run of records as US-China trade tensions have eased and central banks have adopted accommodative monetary policy.
Karl Haeling of LBBW cited comments earlier in the week from President Donald Trump that he would sign a trade deal with China on January 15 as sufficient to keep markets happy.
"It does not matter if it was a good or bad trade deal but what matters is the stability of the tariff rate," Haeling said. "Then companies around the world who were reluctant can rebuild their inventories."
Analysts also cited a policy shift by the People's Bank of China, which said it would lower the amount of cash lenders must keep in reserve.
Briefing.com analyst Patrick O'Hare called the PBOC action "another bottle of champagne to enjoy" after New Year's Day celebrations and one that continued the market's "bullish bias."
Some analysts have warned that the market could be primed for a pullback early in 2020 after rising so much so quickly. But most market watchers do not expect a very deep drop anytime soon due to confidence the United States will avoid a recession in 2020.
Although leading auto manufacturers are expected to report December sales on Friday, the economic calendar the rest of the holiday-shortened week is otherwise fairly quiet.
More traders are expected to be back by next week when there is a heavier schedule of reports, including the December jobs report.