Odds and Edge - Probabilities in Day Trading
The whole concept of odds and probabilities is a subject that most beginner traders avoid, but is absolutely one of every professional trader's secrets for success. Trading the financial markets is all about managing risk, nothing is 100% accurate or works 100% of the time. There is always a certain chance, certain odds, certain probability that a trade will work or wont work. Even if a trading system generates 99% chance of success, there is still that 1% chance of failure. Nothing in trading is black or white, everything is somewhere in the gray. It is the job of the trader to determine how gray the trade is, what are odds of success. The trader can then adjust their trading based on the probability of the specific trade and the probability of the trading system that he uses. By figuring out exact odds of success, the trader can figure out his edge and maintain it.
Why Odds and Edge?
Anyone that has ever been to Las Vegas can see the money that the casinos spend to lure the gambler into their casino. The casinos make their money, an enormous amount of money, by maintaining their edge. In the collection of all games that a casino runs, they still maintain around 4.5% edge. That means that out of every dollar that is brought in to the casino, 4.5 cents stay there. Some people hit the jack pots, some people lose everything they have, but the casino, on average, makes 4.5%. For the casinos, it is not gambling, it is a game of odds, probabilities and they know their edge. The more gamblers come in, the more money they bring with them, the more the casino makes, as long as they maintain their edge.
In trading, the trader runs their own casino. If a trader wins 80% of the time, makes $200.00 every time he wins and loses $100.00 every time he loses, on average the trader makes $140.00 per trade. As long as the trader maintains his ratios, his edge, he will make, on average, $140.00 every time he executes a trade.
This is a very important statistic for a trader. Being aware of these numbers allows traders to weather draw downs, stick to their system, eliminating hesitation and managing their trading correctly.
Odds and Your System
Every trader wants to make money. Even the best analysis, best system in the world will have losing trades, it is just part of the business, there is no 100% success. After a long testing period, every trader should evaluate their statistics to find their edge. What percentage of trades are profitable? What is the average winning trade? What is the average losing trade? What is the average profit per day?
Testing a trading system is a gradual process, as many factors can affect results. By paper trading for a long period of time, a beginner trader can evaluate their trading system. The next step is trading minimum size positions and testing system results again. Keeping a trading diary and tracking performance as the system develops can establish the system's edge and odds of success. These numbers will help the trader become a business and not a gambler.
Odds and Your Individual Trades
Every trading system has certain conditions or parameters that are required before a trade is executed. Depending on the structure of the trading system, there can be more parameters or less parameters. The more conditions are true, the higher the odds of a successful trade. It is almost impossible to find a trade that has all conditions aligned, almost all trades are less than perfect.
Knowing the trade's odds can help a trader evaluate risk and adjust position accordingly. If only 80% of conditions in the trading system exist, the trade has less odds of success than a trade that has 100% of conditions and should be traded differently.
If all trading conditions exist, if all indicators are lined up, the trade has certain odds of success. If not all indicators are lined up correctly, the trade has lower odds of success. Below a certain level of odds, the trade should not be taken.
Thinking in Odds
Most traders have serious problems thinking in odds because it is against our nature to take on a position without being 100% sure that it will be a success. Losing hurts, it is painful, taking a position knowing that there is a chance of loss is usually avoided. Traders want to "know" what is going to happen and therefore look for the black and white in trading. Black and white do not exist in trading.
A trade can be right and still lose. All indicators can be aligned and the trade can still lose. Even if the system is 99% accurate, there is still a chance that the trade will be a loss. Most traders are unable to accept this and it causes frustration. By learning to think in odds, a trader can both vary their trading according to odds of success and accept losing trades a lot easier.
by Shay Horowitz
ps. from FF forums .
