Stock Indexes Rise on Softer Inflation Data as Q3 Trading Concludes

U.S. stock markets opened higher on the final trading day of the third quarter, with the S&P 500 gaining 0.47% and Nasdaq rising 0.90% following a better-than-expected inflation reading showing core PCE inflation increased just 0.2% month-over-month versus the forecasted 0.3%. Private sector employment also beat expectations with 90,000 jobs created in September, exceeding the 70,000 estimate. Federal Reserve Vice Chair John Williams' comments downplaying the likelihood of an immediate rate hike in October helped boost interest rate-sensitive sectors.

The market's upward momentum reflects shifting expectations around monetary policy. Recent economic data painted a more moderate inflation picture than anticipated, with both headline and core measures coming in below forecasts. Employment growth also accelerated from the previous month, suggesting underlying economic resilience despite concerns about rising interest rates and energy costs that dominated third-quarter trading.

Federal Reserve communications have become increasingly influential for investor positioning. Vice Chair Williams' recent remarks about the absence of urgency for consecutive rate increases significantly shifted market pricing, reducing the probability of an October move from around 70% to below 50%. This messaging, combined with cooler inflation readings, appears to have restored investor confidence in interest rate-sensitive sectors including technology and semiconductors.