Over ninety percent of the stocks (in the S&P 500 Index) are in downtrends.
Ten percent are in uptrends, but they're big companies.
And since the S&P 500 Index is capitalization weighted, those 50 stocks, 40 stocks, whatever it is,
dragged the average to all-time highs.
Now, that doesn't mean it's not painful if you short those stocks. But basically, this has happened many times in market history.
It gets narrower, and narrower, and narrower, the advance does, until it's just down to
a few names.
And eventually, they crack, too.