U.S. business activity picked up in April after nearly stalling in the prior month, but supplier delivery times at factories worsened as the war with Iran disrupted supply chains, pushing a measure of output prices to a near four-year high. S&P Global said its flash U.S. Composite PMI Output Index, which tracks the manufacturing and services sectors, increased to 52.0 this month. That followed a 50.3 reading in March, which was the lowest level since September 2023.