The Dow finished up 2 points, or 0.01%, to 27,995, the S&P 500 gained 0.52%, rising for a third day, and the Nasdaq was up 1.21%.
Stocks on Monday had finished broadly higher after several big corporate deals lifted investor sentiment.
“Wall Street appears to have recovered some of its mojo,” said Mizuho Bank in a report. “The question to ask, though, is whether we are dealing with optimism or there is just optimism about deals.”
The tech giant's all-virtual showcase, which was open to the public, is expected to precede another iPhone unveiling later in the fall.
China's official statistics office said Tuesday that industrial production in the world's second-largest economy surged 5.6% in August. That's the strongest reading of the country's most important sector since the global coronavirus pandemic began there in early January. Retail sales in China in August rose for the first time this year.
Stocks in Shanghai had closed Tuesday with a gain of 0.51%.
The Federal Reserve on Tuesday began a two-day meeting, with a decision on interest rates expected Wednesday afternoon. The central bank is expected to hold rates near zero and affirm its new, more relaxed stance on inflation.