Law of Large Numbers
The law of large numbers is a theorem in probability that states that as the number of trials increases, the actual average result will converge to the expected value. In trading, this is the foundational principle that makes expectancy-based trading possible.
It means that a trader with a positive edge will inevitably be profitable if they trade enough times. This law is what allows professional traders to accept a series of losses as part of the process, knowing that their strategy is statistically sound.
It emphasizes the importance of sample size and consistent execution over the outcome of any single trade. Without the law of large numbers, trading would be pure gambling.
It provides the mathematical certainty that enables long-term success in an uncertain environment. Traders must have the patience to allow this law to work in their favor.
It is the reason why consistency is the most important trait in professional trading.