Activity in China's services sector expanded at the fastest pace in three months in August, providing a boost to the world's second-largest economy that has been struggling to reverse a prolonged slump in its manufacturing sector.
The mood also got a lift after Hong Kong leader Carrie Lam withdrew an extradition bill that had triggered months of often violent protests in the Chinese-ruled city.
"This is a sentiment driven market and whenever you get news like this, while it may not directly impact the US, it causes a ripple effect," said Ryan Nauman, market strategist at Informa Financial Intelligence in Lake Taho, California.
Markets struggled last month as escalating trade tensions and the inversion of a key part of the US yield curve, often seen as a sign of recession, drove investors away from risky assets and pushed the S&P 500 to log its worst August in four years.
A contraction in US factory activity in August only added to those concerns on Tuesday.
However, risk sentiment improved on Wednesday, pushing the benchmark US Treasury 10-year yield higher, with the yield curve at its steepest in more than two weeks.
Helping cool slowdown concerns were comments from New York Federal Reserve President John Williams who said the economy appeared to be in a good place and he is ready to "act as appropriate" to help avoid a downturn.
Ten of the 11 major S&P sectors were higher, with a 1.48pc rise in technology stocks providing the biggest boost.
The US nonfarm payrolls report due Friday will also be a critical piece of data, with some analysts cautioning that any weakness could be taken as a major signal that the domestic economy is slowing.
"The strong labor market and consumer is what's driving economic growth and if we start seeing cracks in the labor market, that would give me pause that a recession is on the horizon," Nauman said.
However, he added weakness in the labor market could pressure the Federal Reserve to cut interest rates by as much as 50 basis points in its mid-September meeting. Market participants are currently expecting a quarter percentage point cut.
At 11:53 a.m. ET the Dow Jones Industrial Average was up 207.36 points, or 0.79pc, at 26,325.38, the S&P 500 was up 26.18 points, or 0.90pc, at 2,932.45 and the Nasdaq Composite was up 81.60 points, or 1.04pc, at 7,955.76.
Bank stocks rose 0.93pc, bouncing back from a selloff on Tuesday when the 10-year US Treasury yield hit its lowest since July 2016.
Tyson Foods Inc shares fell 5.8pc to the bottom of the S&P 500 after the United States' biggest meat processor cut its 2019 earnings forecast.
Starbucks Corp dropped 1.36pc after the company said it expects 2020 adjusted profit growth to be lower than 2019 and hinted at fewer share repurchases next year.
Advancing issues outnumbered decliners by a 4.11-to-1 ratio on the NYSE and by a 2.06-to-1 ratio on the Nasdaq.
The S&P index recorded 59 new 52-week highs and three new lows, while the Nasdaq recorded 49 new highs and 56 new lows.