Two calendar quirks have held up for decades. September has been the weakest month for U.S. stocks on average since 1950 — the only month with a consistently negative long-run return — while October is the most volatile, home to the crashes of 1929, 1987, and 2008.

Japanese stocks compounded at roughly 17% a year through the 1970s and nearly 29% a year through the 1980s — turning $10,000 in 1970 into about $610,000 by 1989. The bubble then burst so completely that the Nikkei 225 didn’t reclaim its December 1989 peak until February 2024, a 35-year round trip.

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.

Warren Buffett is one of the greatest investors of all time — and for a moment he looked completely out of step. In the 20 months leading into the March 2000 dot-com peak, Berkshire Hathaway’s stock fell about 45% while the Nasdaq 100 nearly tripled. Buffett was right in the end; it just took longer than the market’s patience.