**Hotter-than-expected September CPI data released October 14 drove the main sentiment shift for S&P 500 levels during the week of October 12, 2026.** The print showed headline inflation rising more than consensus, lifting market-implied odds of additional Federal Reserve rate hikes by year-end and pressuring rate-sensitive AI and growth stocks. The index opened the week near its October 6 record close of 7,818.93, trading around 7,800–7,807 early on mixed bank earnings (JPMorgan missed estimates while Goldman Sachs beat), before falling sharply mid-week to close October 14 at 7,718.94. A modest rebound followed on Thursday amid sector rotation into healthcare and stronger bank results elsewhere, with the S&P finishing October 15 at 7,744.06. Rising 10-year Treasury yields near multi-decade highs, elevated oil prices, and upcoming catalysts including October 15 PPI/retail sales, monthly options expiration, and the late-October FOMC meeting added to volatility and uncertainty around near-term index thresholds.