Has Trumphoria finally hit a wall?

When talking about stock markets, there are three rules you have to remember. First, the stock market is not the economy. Second, the stock market is not the economy. Third, the stock market is not the economy.

So the market plunge of the past few days might mean nothing at all.

On one side, don't assume that there was a good reason for the slide (although the fact that the Dow fell 666 points on Friday hints either at satanic forces or at some mystical link with the Kushner family's bum investment at 666 Fifth Ave). When stocks crashed in 1987, economist Robert Shiller carried out a real-time survey of investor motivations; it turned out that the crash was essentially a pure self-fulfilling panic. People weren't selling because some news item caused them to revise their views about stock values; they sold because they saw that other people were selling.