In exhibit 11, we update this analysis for the S&P 500, an index of the largest U.S. public companies, from 1988 to 2025. Consistent with past research, plausible reasons support some of the big moves, but others defy simple explanation (e.g., “Late rally on Wall Street as rebound in stocks defies latest economic news.”). This line of research makes clear that changes in asset prices have fundamental and…