The average daily odd-lot trading divided by total market volume for the day. In other words, it is the ratio of odd-lot sales and purchases divided by (2 × total market volume for the day):

Odd-lot trading ratio = (odd-lot sales sales + odd-lot purchases)/ (2 × total market volume)

The number (2) in the denominator is meant to cut the volume in half because it represents a sale and a purchase together as one unit. A normal figure of this ratio is 10%. Below 10% indicates a bullish trading. Above 10% suggests a bearish trading.

This ratio is known for short as OLTR.