The Dow Jones industrial index rose 0.6 percent, the broad S&P 500 index 0.7 percent, and the technology-heavy Nasdaq composite index 0.9 percent.
Electric car manufacturer Tesla rose sharply and closed up 5.3 percent after media reports that CEO Elon Musk will leave his role in the White House within a few weeks.
Tech giant Amazon rose 2 percent. During the day, reports emerged that the company had made a bid for the American operations of the Chinese social media service Tiktok.
Otherwise, market players are waiting for Donald Trump's announcement regarding direct import tariffs against all countries that have, in his view, trade barriers against the US.
The announcement is expected to come after the stock market closes at 22.00 Swedish time.
A Ceiling
Investors hope for lower tariffs than the 20-25 percent the White House previously mentioned.
At the same time, Finance Minister Scott Bessent said on Wednesday that the published percentage figures will constitute a ceiling, a highest possible level – which gives other countries the opportunity to take steps to lower the level.
The uncertainty surrounding the tariffs has hit the world's stock markets hard. Speculations are now many about what they will entail, but as of Wednesday evening, several alternatives were reportedly on the White House's table – and commentators are far from certain about getting clarity.
"Increased Uncertainty"
Vail Hartman and Ian Lyngen, analysts at the consulting firm BMO Capital Markets, write to the news agency Bloomberg that Trump's announcement is unlikely to offer "anything definitive" and they continue:
"As a result, increased uncertainty and volatility are likely to arise."
Nor does Jon Brager, portfolio manager at Palmer Square Capital Management, believe that complete clarity will emerge after Trump's announcement.
We expect to learn much more from the president today, but we also believe that the market will continue to be tense until we know about reprisals and, or, escalating measures or rhetoric from the major trading partners, he says to CNBC.
