Edge

Your advantage over the market's price, the gap between your estimate of an outcome's true probability and the price you can trade it at, net of fees.

Edge is the only durable source of profit. Without it you're paying fees to gamble; with it, disciplined sizing turns the edge into compounding returns. Measuring whether you actually have an edge, by market, is the point of analytics.

Edge is the advantage you have over the market price, the gap between an outcome's true probability and the probability implied by its price. If you can reliably identify outcomes the market has mispriced, you have edge, and edge is the only durable source of trading profit. Everything else is variance.

Edge is hard-won and easy to overestimate. It comes from better information, better models, faster reaction, or a structural advantage, not from confidence or recency. The honest test is whether your estimate of true probability is genuinely better-calibrated than the market's, which you can only know by tracking your results over many trades against the prices you paid.

Real edge is also fragile to costs. A 3-cent edge on probability is erased by a 3-cent round trip of spread and fees, so edge has to be measured net of trading costs. The combination of a genuine probability advantage and disciplined cost control is what turns an idea into a profitable strategy.