Also of note is that in September, the S&P 500's forward P/E ratio hovered around 21, above the long-term average of 16. Thankfully, Powell wasn't predicting any kind of immediate market crash, but he was simply stating what the data was clearly showing: the "margin of safety" for investors felt dangerously thin. Historically, such elevated valuations had been a reliable predictor of flat or negative returns in the following decade.When Powell spoke in September 2025, his message was pretty straightforward ...