Stocks are under pressure Wednesday afternoon as inflation fears come to the forefront. Here's what is moving markets:

Geopolitical uncertainty is back in focus: Investors have been closely watching chatter from the United States and Iran at the United Nations General Assembly. U.S. envoy to the Middle East Steve Witkoff said in a Tuesday post on X that both sides are in talks through mediators whose discussions "we hope will prove constructive and promising." In earlier remarks, President Trump said he had to decide whether to make a deal with Iran or "annihilate" the country.

... And oil prices and U.S. bond yields are reacting: Brent crude rebounded 3% Wednesday, pushing prices above $102 a barrel. Yields on the U.S. 10-year Treasury forged above 5%. New economic data is also weighing on top of this week's precarious diplomatic discussions. Fed governor Michael Barr said he expects additional interest rate hikes will be needed to tamp down inflation; Richmond Fed President Thomas Barkin suggested the same yesterday.

U.S. business activity accelerated to a more than five-year high, further fanning inflation worries as input costs, like energy prices, continue to climb. Manufacturing and services activity, measured by S&P Global's U.S. PMI, rose to 57 and 58.7. Both numbers beat expectations from economists polled by the Wall Street Journal.