History Says No 20-Year Stretch in the S&P 500 Has Lost Money Since 1950. Here's What the Worst One Returned.

Analysis of S&P 500 data from 1950-2026 shows that no 20-year investment period has resulted in losses. The weakest stretch (March 1962-March 1982) gained 61% on price alone, but inflation eroded most gains. With reinvested dividends, even the worst period returned 237%, though inflation reduced real returns to just 7% over 20 years. The median 20-year return was 279% on price, suggesting long-term S&P 500 investing near record highs remains historically sound.