In our last lesson we looked at how most traders pick a standard amount to trade per certain amount of equity in their account and how this probably isn’t the best way to maximize profits and minimize losses of a potential long, medium or short-term trading strategy. In this lesson we are going to look at the two categories that most position sizing strategies fall into which are known as martingale strategies and anti-martingale strategies.
A position sizing strategy which incorporates the martingale technique is basically any strategy which increases the trade size as a trade moves against the trader or after a losing trade. On the flip side a position sizing strategy which incorporates the anti-martingale technique is basically any strategy which increases the trade size as the trade moves in the traders favor or after a winning trade.
The most basic martingale strategy is one in which the trader trades a set positionsize at the beginning of his trading strategy and then double’s the size of his trades after each unprofitable trade, returning back to the original position size only after a profitable trade. Using this strategy no matter how large the string of losing trades a trader faces, on the next winning trade they will make up all their losses plus a profit equal to the profit on their original trade size.
As an example lets say that a trader is using a strategy on the full size EUR/USD Forex contract that takes profits and losses both at the 200 point level (I like using the EUR/USD Forex contract because it has a fixed point value of $1 per contract for mini forex contracts and $10 per contract for full sized contracts but the example is the same for any instrument)
The trader starts with $100,000 in his account and decides that his starting position size will be 3 contracts (300,000) and that he will use the basic martingale strategy to place his trades. Using the below 10 trades here is how it would work:
As you can see from the above example although the trader was down significantly going into the 10th trade, as the 10th trade was profitable he made up all his losses plus brought the account profitable by the equity high of the account, plus original profit target of $6000.
At first glance the above method can seem very sound and people often point to their perception that the chances of having a winning trade increase after a string of losing trades. Mathematically however the large majority of strategies work like flipping a coin, in that the chances of having a profitable trade on the next trade is completely independent of how many profitable or unprofitable trades one has leading up to that trade. As when flipping a coin no matter how many times you flip heads the chances of flipping tails on the next flip of the coin are still 50/50.
The second problem with this method is that it requires an unlimited amount of money to ensure success. Looking at our trade example again but replacing the last trade with another losing trade instead of a winner, you can see that the trader is now in a position where, at the normal $1000 per contract margin level required, he does not have enough money in his account to put up the necessary margin which is required to initiate the next 48 contract position.
So while the pure martingale strategy and variations of it can produce successful results for extended periods of time, as I hope the above shows, odds are that it will eventually end up in blowing ones account completely.
With this in mind the large majority of successful traders that I have seen follow anti-martingale strategies which increase size when trades are profitable, never when unprofitable, and these are the methods which I will be covering starting with the next lesson.