A short-term (intraday) technical indicator (specifically a breadth indicator) that measures the difference between the number of stocks trading on an uptick versus the number of stocks trading on a downtick. It is a minute-by-minute equivalent of the daily advance-decline line and serves the same purpose. The TICK of a stock can have only 2 values, either +1 or -1. When a stock’s last traded price is higher than the previous trade, its TICK value is set to + 1. And when its last traded price is lower than the previous trade, its TICK value is set to – 1. If the last trade is executed at the same price as the previous one, then the up/ down tick status remains unchanged.

The Tick index helps to detect short-term (usually sub-minute level) extreme overbought conditions. It is also a good instrument for detecting possible trend changes when its strength or weaknesses diverge from the futures contract being traded on respective stocks. A combination of the TRIN index and the TICK index in intraday trading would imply that a rising TICK and a declining TRIN have positive readings, whereas it would indicate that a declining TICK and an advancing TRIN have negative readings.