Recent August CPI data showing a 0.4% month-over-month headline increase, driven largely by a 3.9% jump in gasoline prices amid energy supply shocks and trade tensions, has anchored expectations for September's reading near 0.4% or 0.5%. Market-implied odds remain tightly clustered because persistent upward pressure from fuel costs and tariffs competes with moderating trends in shelter and core goods, while the University of Michigan survey's year-ahead inflation expectations rose to 4.6% in early September. Traders are weighing these factors against the Federal Reserve's imminent policy decision and the typical volatility in monthly energy components, with the upcoming October 14 release serving as the key catalyst that could shift probabilities depending on whether headline prints soften below 0.3% or accelerate above 0.5%.