The long/short ratio expresses how a group of traders is positioned by dividing long exposure by short exposure. A ratio above one means longs outnumber shorts; below one means the reverse. Exchanges publish these ratios for different cohorts, such as all accounts or only top traders, and the figures can differ between them.
The metric is used as a sentiment and positioning indicator. A heavily one-sided ratio shows that the crowd is leaning strongly in a single direction, which some observers interpret as crowded positioning.
It is important to read the ratio carefully. Different data sources define and weight it differently, and a ratio reflects current positioning rather than predicting outcomes. It describes how participants are arranged, not how price will move.