A technical market indicator that involves relative odd-lot short trading by small investors. This ratio relates odd-lot short sales over some time period to the total number of short sales:

Odd-lot short sale ratio = odd-lot short sales/ total number of short sales

Typically, the odd-lot short ratio is calculated by taking a ten-day moving average of odd-lot short sales divided by total odd-lot short sales. This ratio indicates the market sentiment of small investors who buy less than 100 shares of stock (odd-lot). Small investors are usually wrong about the direction of the market and therefore this market indicator is viewed to be a contrary opinion sentiment indicator.