Historical P/E, 1920–Present
The line traces the trailing P/E each month. Dashed reference lines mark the 80th percentile (historically expensive) and 20th percentile (historically cheap) over the full period. The vertical axis is logarithmic so the 2009 earnings-collapse spike stays legible.
Overview
The price-to-earnings (P/E) ratio measures how much investors pay for each dollar of the S&P 500’s trailing earnings. It is one of the most widely watched gauges of whether the U.S. stock market is cheap or expensive relative to its own history.
Across more than a century of monthly readings, the ratio has typically hovered in the mid-teens, punctuated by sharp extremes: single-digit lows during the inflation-scarred late 1970s and early 1980s, and dramatic highs such as the dot-com peak around 2000 and the 2009 spike, when collapsing earnings mechanically inflated the ratio far above 100.
Today the ratio sits above its long-run median, closer to the upper end of its historical range than the lower — a level that has historically signalled richer-than-average valuations.
Key Statistics
Computed over all monthly observations from 1920 to present.
Current P/E
—
latest month
High P/E
—
80th percentile
Low P/E
—
20th percentile
Median P/E
—
50th percentile
Data & Citations
Recent months may be estimates (marked † at the source). Underlying data is
derived from Robert Shiller’s dataset. This report embeds a static snapshot of
the series; re-run scrape.py to refresh.
View full data table (— months)
| Month | P/E |
|---|