The red dot is where we were on Friday; some are saying it could hit 6,000 or 4,000, also indicated (adjusted for CPI as at the end of September 2008).
The question is, how much of the fantastic gain of the past 20 years or so will be undone, and over what period? Where would you say we "ought" to be? (Not that Mr Market cares, obviously.)
Connect up the lows of the early 30s and the 70s and extend the line, and you get what? An implied 2,500 or so. Connect up the highs of 1929 and the 50s and extend the line, and you end up about where we were at the start of this month, nudging 11,000.
Karl Denninger is now talking about the S&P 500 falling to 500 points, a level it first broke above in March 1995; this would mean a further c. 50% drop from its close on Friday.
And he gives his reasons (plausible to me) why the American economy is in worse shape to overcome the setback, than it was in the 1930s.