Predictions are hard..................

............................................................especially about the future:

"Stock prices have reached what looks like a permanently high plateau," declared the eminent Yale economist Irving Fisher in the autumn of 1929.  A few weeks after this oracular pronouncement, the Dow Jones Industrial Average had declined by more than a third.  The worst was still to come.  On 8 July 1932, the Dow Jones closed at 41.88, a drop on nearly 90 percent from its 1929 peak.

Edward Chancellor,  Devil Take The Hindmost:  A History Of Financial Speculation