Kevin Dietsch/Getty, Tyler Le/BIHeadline inflation fell to 2.5% in August, the lowest in over three years.But core CPI rose 3.2%, causing investor concern about persistent inflation and higher rates.Experts warn rate-cut expectations may be too high given the latest inflation data.Headline inflation fell to 2.5% year-over-year in August, dropping significantly from 2.9% in July to its lowest level in over three years.Yet the report spooked investors, with the S&P 500 falling 1.4% in the first hour and a half of trading on Wednesday because a secondary inflation measure came in a touch too hot.Core CPI, which measures price growth outside housing and food due to their volatility, rose 3.2% year-over-year.