The Most Expensive Quote in History: "Permanently High Plateau"

Irving Fisher was one of the most respected economists of his era when he uttered these words just days before the 1929 stock market crash. The Dow Jones Industrial Average would go on to lose nearly 90% of its value over the next three years.

The crash triggered the Great Depression, the worst economic downturn in modern history. Fisher himself lost a fortune — estimated at $10 million (equivalent to roughly $180 million today) — and had to be bailed out by Yale University.

His quote has become the gold standard for overconfident market predictions and is the reason we now have the phrase "famous last words" in investing.