Click on any chart to engorge it

Click on any chart to engorge it

Nasdaq Volume Indicator

Over the last year, the total daily Nasdaq volume compared to the total NYSE volume has been a good indicator of stock market tops.  The logic would seem to be that as investors get too bullish, more of their money goes into the "riskier" companies of the Nasdaq, and they are immediately rewarded accordingly.  This chart comes from Matthew Frailey at Stockcharts.com