S&P 500 Long-Term Gains Depend on Few Trading Days

Analysis of S&P 500 data from 1928 through August 12, 2026, reveals that long-term stock market gains are concentrated in a very small number of trading days. Specifically, removing just 94 of the best-performing days—approximately 0.36% of all trading days—would turn the index's net return negative over that period.

CFRA reports that while some investors employ buy the dip strategies to avoid missing these peaks, data from 1980 onward suggests market timers often maintain higher equity exposure during the worst days than the best. Sam Stovall, chief of investment strategy at CFRA, noted that these strategies have increased the fear of missing out among investors.

Research by Brad Cornell, professor emeritus of financial economics at UCLA's Anderson Graduate School of Management, indicates that many of the largest one-day spikes occur during bear markets. This suggests that investors must remain heavily invested during downturns to capture the gains necessary for long-term growth.