Basic Probabilities to Understand

Feb 20, 2024By The Kaizen Trader


Probabilities, in essence, encapsulate the likelihood of various outcomes occurring within a given set of circumstances. In the realm of trading, understanding probabilities is paramount, as it provides insight into the potential outcomes of trading decisions.

Every trader should be well-versed in a basic set of probabilities relevant to their strategy. Presented below is a list for all traders to grasp when deploying their strategies.

Winning and Losing Trades: Understanding the probability of winning and losing trades is fundamental to risk management and overall strategy evaluation.
Example: Suppose a trader has a strategy with a historical win rate of 30%. This means that, on average, they win 30 out of every 100 trades. By knowing this probability, the trader can anticipate that they will experience losing trades as well, even with a successful strategy. 

Using that 30% win rate we can calculate the probabilities of losing streaks over a set number of trades. Below is an image shared by Steve Burns detailing the probabilities of losing streaks by win rate for a 50 trade period. We can see there is a 69% chance of losing 10 trades in a row over 50 trades with a 30% win rate strategy.

person using MacBook Pro

Days, Weeks, Months, and Years: Recognising the probabilities of trading outcomes over different timeframes helps traders gauge the consistency and sustainability of their strategies.
Example: A trader may analyse their strategy's performance over various timeframes to understand its efficacy. For instance, traders can utilise this analysis to comprehend the likelihood of consecutive losing days, weeks, or months, which is particularly crucial from a trading psychology standpoint, aiding in managing emotions and fostering better decision-making.

Drawdown Depth: Understanding the probabilities associated with drawdowns is pivotal for navigating emotional challenges and ensuring resilience in adverse market conditions.

Example: Consider a trader meticulously analysing the probabilities of experiencing drawdowns of various magnitudes. They may find, for instance, a 25% chance of encountering a 10% drawdown in a year, or a 50% likelihood of facing a 5% drawdown within the same timeframe. Armed with this information, the trader gains not only a clearer view of potential risks but also a psychological advantage. By grasping the likelihood of such drawdowns, the trader can mentally prepare themselves for inevitable downturns, fostering emotional resilience and maintaining discipline in their trading approach. This insight empowers the trader to stay focused on long-term goals, effectively managing emotions and optimising decision-making processes amidst market volatility.

A distinct lack of understanding around probabilities often leads to psychological challenges for traders, which in turn can result in poor decision-making. By grasping these probabilities, traders can better anticipate and manage both the best and worst-case scenarios, thus effectively managing their expectations during both prosperous and adverse market conditions.