U.S. business activity slowed in September to its weakest pace in three months, Bloomberg reports. Service-sector costs rose to their highest since May, but companies struggled to raise selling prices, squeezing margins. New orders and backlogs grew at their slowest in three months, and employment dipped to a five-month low. Despite the weaker momentum, firms remained optimistic about the year ahead, citing potential benefits from lower interest rates and stronger domestic production fueled by tariffs. With business sentiment still upbeat, companies appear hopeful that softer demand growth will prove temporary rather than a sign of deeper slowdown.