NYSE TRIN

http://emini-watch.com/free-stuff/trin-indicator/

Trin

The Trin is a breadth oscillator which aids in the measurement of internal market strength or weakness. Also known as The Arms Index (because it was invented by Richard Arms), the Trin is an acronym that stands for The Trading Index.

The Trin measures volatility within the stock market. The Trin represents the relationship between advancing and declining issues by measuring their volume flow. The Trin is commonly used as a short term trading tool.

The Trin also has an inverse relationship with the Tick. In contrast to the Tick, a rising Trin signals that the Bears are beginning to take control. Likewise, a falling Trin tells us that the Bulls are taking control of the direction of the market because a falling Trin shows us that more volume is flowing into advancing stocks than declining stocks.

The formula for the Trin is as follows:

Advancing Issues / Declining Issues
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Advancing Volume / Declining Volume

This formula, like the Trin itself, helps us to descern whether volume is flowing into advancing or declining issues. The Trin will read under 1.0 when advancing stocks are the major source of volume and above 1.0 when declining stocks are the predominant source of volume flow in the market.

In Brief:
A rising Trin depicts a weak market and a falling Trin depicts a strong market.