US stock futures fell after Nvidia revealed costly new curbs on chip exports to China, and investors grappled with uncertainty over President Trump's trade policy.

Wall Street index futures dropped on Wednesday and chip darling Nvidia slumped after the company flagged steep charges from new U.S. curbs on chip exports to China, fuelling worries about the fallout of an escalating trade war.

US stock futures were lower after chip darling Nvidia warned of a $5.5 bln charge linked to a U.S. export ban on some chips.

Who do they believe wins the conference finals, who claims the NBA Championship, and what player jumps to the forefront of conversations on talk shows and social media as the playoffs unfold. We have thrown in the odds where it is appropriate.