How To Back Test Your Trading System? Know These Shocking Limitations!
Developing a trading system is not easy. It requires first of all good trading experience. Than you need to test your trading system under live trading conditions. It might take time as well as involve the risk of losing money. To overcome this difficulty in testing a trading system or a trading strategy, backtesting has been developed. Backtesting is possible with the use of software. A trading system might comprise of a set of two or more indicators with a set of rules that tell when to enter or exit the trade.
For this you can do back testing. Back testing is a method that uses historical data to test how well your indicators work in a particular market. You can use back testing software that enables you to look at the past market data and test how well the indicators and your trading system have worked in the past market.
Backtesting results are no guarantee that the trading system will perform well under live market conditions. Things that worked in the past might not work now. Similarly something that didn’t work in the past, may work now! You never know!There are many problems with historical data. There is no slippage in backtesting. Slippage is one of the most important problem that a trader faces while trading live. The other problem that the backtest ignores is the widening of spreads under volatile market conditions.
In other words, no two trades work out in exact the same way twice. SO you have to be careful when looking at the back testing results and take it with a pinch of salt. However, there are still some advantages of back testing a trading system.
Back testing can give you a feel how a particular market behaves under certain conditions. Back testing can also spot you certain general characteristics of the market like the seasonal trends and market tendencies.
For example, some markets especially the commodities market is highly seasonal and cyclical in nature. We can take the example of agricultural commodities like wheat, grains,corn, cotton, coffee and stuff like that. In case of the stock market, there is much talk of the January Effect. Well, it is there no doubt about it. Some years, it is highly pronounced and others it is not that pronounced. Similarly stock prices tend to rise at the end of each month and the first few days of the new months. The reason for this is that many institutional investors tend to put the new funds to work at the end of the month and the beginning of the new month! Now in other markets, you might not find any seasonal trends. For example, there is very little seasonality in curreny market or the bond market.
Back testing can also help you establish the amount of time a particular market tends to run in a certain direction. For example, in case of US Dollar Index, its trend lines tend to last for months to years.
But to tell you the truth, backtesting can only give you a rough guess about the performance of the trading system under live trading conditions. There is no substitute for live trading results!
Mr. Ahmad Hassam has done Masters from Harvard University. Download these Forex Scalping Cheatsheets FREE! Read this shocking FREE 40 page PDF FRWC Brutal Truth Report that exposes everything about trading robots!
