There is a whole industry of forecasters who make outlandish projections to sell their newsletters or books. Overall I am not sure they help anyone very much.
As Peter Lynch said “Far more money has been lost by investors preparing for corrections, or trying to anticipate corrections, than has been lost in corrections themselves.”
The optimist says the glass is half full. The pessimist says the glass is half empty. The realist says the glass is both half full and half empty.
Investing is an extremely difficult endeavour, and most will fail at it.
All the charts in the world that show stocks have averaged X return over Y period of time are useful only to the extent that investors realise that there were countless periods when stocks lost 10, 20, and even 50% along the way to averaging those returns.
While we should heed the counsel of wise men, we should be on guard against the Eeyore's of the world (from Winnie The Pooh), who have wedded themselves to a bearish idea, and who point an accusatory finger at those of us who choose to ignore their warnings.
It is to the great misfortune of “the bearish forecaster” that he has been more preoccupied with being right about the inevitable doom of our investments, at the expense of ignoring the catastrophe suffered by their own.