Regression to Trend: S&P Composite 170% Above Trend in September
Published on October 4, 2024
Quick take: At the end of September, the inflation-adjusted S&P 500 index price was 170% above its long-term trend, up from August.
About the only certainty in the stock market is that, over the long haul, over-performance turns into underperformance and vice versa. Is there a pattern to this movement? Let's apply some simple regression analysis to the question.