Since 1970, the Dow has closed higher on only about 52% of trading days — barely better than a coin flip on any given day. Nearly all of the index’s long-run gain comes from compounding a slight edge across tens of thousands of days, not from picking winning days.

The only four-year losing streak in Dow history is the Great Depression: the index fell 17% in 1929, 34% in 1930, 53% in 1931, and 23% in 1932. 1931 remains the worst calendar year the Dow has ever recorded.

The Dow closed at 381.17 on September 3, 1929, right before the crash. It did not close above that level again until November 23, 1954 — nearly 25 years later.

The Dow spent the entire 1970s going almost nowhere. It closed 1969 at 800.36 and closed 1979 at 838.74 — a gain of just 38 points, in price terms, across ten full years.