When the NYSE up volume minus down volume looks like it does in the chart below, trading against the trend can be hazardous. Even during the periods of sideways movement today, the line has just kept dropping. And its at a level (-800,000K) that is very bearish. Its rare for the market to turn around when the up-down volume line looks like this (but then again, it is OPEX, so anything can happen - unless it all happened yesterday afternoon):
SPX - $VOLD 2 min chart:
