Market cap of the largest stock relative to the 75th percentile stock (x, lhs) and weight of the top 10 stocks in the S&P 500 (%, rhs). Monthly 1925–present.
| Metric | Value |
|---|
| Largest / 75th percentile (latest) | — |
| Top-10 weight (latest) | — |
| Ratio percentile vs. full history (1925–) | — |
| Peak: Great Depression (May 1932) | ~725x |
| Peak: AT&T / GM / IBM era (Nov 1963) | ~475x |
| Peak: Nifty Fifty (1973) | ~475x |
| Peak: Dot-com bubble (2000) | ~560x |
| Peak: Covid pandemic (Mar 2020) | ~560x |
| Peak: AI bubble (Apr 2025) | ~925x |
| Live data source | awaiting fetch… |