Trading System Back Testing! 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.
How to do backtesting? Using a backtesting software makes it very simple and easy. Backtesting uses historical data to test the performance of the trading system under the past market conditions.
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. So 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!
So when you look at back testing results, you should look at them with scepticism. But it doesn’t mean that backtesting is entirely useless! What we can say is that no two trades are exactly alike.
Back testing can also spot you certain general characteristics of the market like the seasonal trends and market tendencies. Back testing can give you a feel how a particular market behaves under certain conditions.
For example, some markets especially the commodities market is highly seasonal and cyclical in nature. 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. 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!
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.
There is no substitute for live trading results! To tell you the truth, backtesting can only give you a rough guess about the performance of the trading system under live trading conditions.
Mr. Ahmad Hassam has done Masters from Harvard University. Download this powerful secret Fibonacci Retracement Method FREE that pulls 500+ pips per trade! Read this shocking FREE 40 page PDF FRWC Brutal Truth Report that exposes everything about trading robots!
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