S&P 500 Shiller P/E Ratio Is Approaching Dot-Com Era Levels [oc]

We examined the S&P 500 Shiller P/E ratio using data from Multpl.com and visualized the trend in R using ggplot2 to compare today’s valuations with past extremes.

Key takeaways:

• Dot-com bubble (1999–2002): Peak Shiller P/E of 44.2
• 2023–2025: Recent reading near 40.4, placing today’s valuation in historically elevated territory
• While today’s economic structure differs from the 1990s, the long-run context shows how rare it is for valuations to reach this zone

Data Source:

• Shiller P/E historical data from Multpl.com
• Visualization built in R (ggplot2)
• By Forensic Economic Services LLC (Rule703.com)