Win Rate
Win Rate is the proportion of completed trades (or markets) in which the strategy produced a positive return.
The math
Win Rate = W / NW = number of winning trades, N = total number of completed trades.
Why it matters
Win Rate is easy to understand and easy to compare across strategies. On prediction markets specifically, it has a natural coin-flip baseline: a strategy that buys randomly would win roughly as often as the market implied probability suggests. A win rate significantly above that baseline, confirmed by Wilson CI, signals genuine skill.
Win Rate says nothing about the size of wins vs losses. A strategy that wins 70% of the time but loses 5× its wins on each loss is a losing strategy. Always read Win Rate alongside average win and average loss, or a profit factor. Bacon (2008) labels it "hit rate" and explicitly warns against treating it as a standalone metric.
Published source
Bacon, C. R. (2008). Practical Portfolio Performance Measurement and Attribution (2nd ed.). Wiley.