October CPI shock: 3.2% vs 3.3% expected, S&P 500 surges 1.9%

October 2023 CPI released November 14 beat expectations across the board. Headline printed 3.2% YoY (vs 3.3% expected), core 4.0% (vs 4.1%), and crucially the monthly core pace eased to 0.2%, putting annualized core inflation near the Fed's 2% target on a 3-month run rate. Energy, goods, and even shelter showed deceleration. The print confirmed the disinflation thesis that had been stuttering through Q3.

The rally was violent and broad. The S&P 500 gained 1.9%, the Russell 2000 surged 5.4% (one of the best single sessions for small caps in years), and the 10Y Treasury yield fell 21 bps from 4.64% to 4.43%. The dollar fell 1.51%, its worst session in a year. VIX dropped to 14.16, signaling the unwinding of recession/policy risk premium that had built through October.

The session catalyzed a year-end rally that took the S&P 500 up 9% from November 14 through year-end and set the stage for 2024's 25% S&P gain. Terminal rate expectations stopped rising; the market began pricing 2024 cuts. Combined with Powell's Jackson Hole August caution and the November 1 FOMC pause, the October CPI print represented the inflection from "higher for longer" to "disinflation landing." The November 14 print is one of the foundational sessions of the 2023-2024 soft-landing regime.