Humphry,The TRIN is the advance/decline ratio divided by the...

Humphry,

The TRIN is the advance/decline ratio divided by the advance volume/decline volume ratio:

((Advancing issues/declining issues) / (advancing volume/declining volume))

For the TRIN to suggest that the market is near a major top, you will notice consecutive (5 or more days) TRIN readings under 1.0.

If you see a reading of 2 or more pop up, it suggests that the market is oversold for the time being (that day) and a bounce (attempt atleast) will likely follow the next trading day.

Here is a chart to keep watch of -

http://stockcharts.com/h-sc/ui?s=$trin