CPI Gains Come and Go

Sep 14, 2023

The S&P 500 managed to rise 0.12% on Wednesday in the wake of the CPI release.  That is the fifth month in a row in which the S&P 500 rose in response to a CPI print, and only two months over the past year (February and April) have seen negative reactions.  Although the S&P has consistently risen on CPI days, the size of the moves have been less substantial than they were previously. As shown below, taking a rolling 10-day average of the S&P 500’s daily change on days that CPI is published shows the average performance remains positive but has turned lower versus a couple months ago when the average move was above 1.2%, which was some of the strongest reactions in a decade and a half.

Although S&P 500 performance has been positive on the day of CPI releases over the last year, looking one week out, the results have been less positive.  As shown below, the S&P has consistently fallen in the week after CPI releases. Again taking a rolling 10-day average, one week performance has been negative for 20 months in a row, or every month since the start of 2022.