The Traders Index, also called Arms Index after inventor Richard Arms. A complex fractional equation that takes into consideration the number of advancing stocks versus the number of decliners and also the respective volume of those two groups. Although TRIN readings over 1.0 are interpreted as bearish and readings below 1.0 are bullish it is the trend of the TRIN that is most important and any discussion of TRIN will always be in context of the trend.