What is Probability?
Probability is a number from 0 to 1, or 0% to 100%, that says how likely something is to happen. A fair coin landing heads has a probability of 0.5. A win rate is a probability only if it is measured on enough trades and stays roughly the same over time.
Why Probability matters
Every trading statistic, from win rate to the odds of a losing streak, is a probability underneath.