The Roaring Twenties roared loudest and longest on the New York Stock Exchange. Share prices rose to unprecedented heights. The Dow Jones Industrial Average increased six-fold from sixty-three in August 1921 to 381 in September 1929. After prices peaked, economist Irving Fisher proclaimed, “stock prices have reached ‘what looks like a permanently high plateau.’” 1
The epic boom ended in a cataclysmic bust. On Black Monday, October 28, 1929, the Dow declined nearly 13 percent. On the following day, Black Tuesday, the market dropped nearly 12 percent. By mid-November, the Dow had lost almost half of its value. The slide continued through the summer of 1932, when the Dow closed at 41.22, its lowest value of the twentieth century, 89 percent below its peak. The Dow did not return to its pre-crash heights until November 1954.
So Professors of Economics can be just as silly as you.