The TRIN is calculated by first dividing the number of stocks that advanced in price by the number of stocks that declined in price to determine the Advance/Decline Ratio. Next, the volume of advancing stocks is divided by the volume of declining stocks to determine the Upside/Downside Ratio. Finally, the Advance/Decline Ratio is divided by the Upside/Downside Ratio. In mathematical terms, the TRIN looks like:
(Advancing Issues / Declining Issues)
(Advancing Volume / Declining Volume)
Like the VIX and put to call ratios, the TRIN is a contrarian sentiment indicator. Generally, a rising TRIN indicates increasing bearish sentiment and a falling TRIN reflects increasing bullish sentiment. I have included the traditional 1.2 and 0.8 thresholds as indicative of sentiment extremes. These are levels at which the probability of a market reversal increases.
Depending on their trading time frame, practitioners use different bars for the TRIN. In the chart below, I chose to use 60 minute bars over the course of a two month period to generate swing signals of the short to intermediate-term variety. For comparison purposes, day traders frequently use 5 or 10 minute bars. It is important to note that different length bars give very different signals and also usually require a rethinking of where one should place the threshold levels for market turns.
At the moment, the TRIN is generating a fairly bullish signal – certainly the most bullish signal since Thanksgiving, when the markets began a strong rally that surprised many who were not watching the TRIN closely.
I will have more on the TRIN in 2008.