The Two Trading Camps
Consider another way in which the fight between the left and right hemispheres affects trading, in the ideological battle between discretionary (gut) and system (left-brain) approaches. The trading world is divided into two fairly distinct camps. The largest camp consists of traders who consider trading an art, those who are called discretionary traders. A smaller group consists of traders who use a specific set of rules to make their trading decisions. These traders are known as system traders.
Often when traders first meet each other, they ask if the other trader is a discretionary or system trader. For most successful traders, the answer is rarely black and white, because trading styles generally fall on a continuum between the purely intuitive discretionary trader and the purely rule-oriented system trader. Individuals who think of themselves as discretionary traders range from shoot-from-the-hip traders who buy and sell when it feels right, to more methodical traders who use combinations of chart patterns and mathematical indicators to trade only when a set of conditions have been met. Investors who think of themselves as system traders range from traders who use such a specific set of rules that they can be programmed into a computer, to those who use a loose set of rules in combination with their own ability to recognize certain patterns and market conditions.
The best discretionary traders tend to be right-brain dominant, using their intuition to decide when to make trades. This tendency is especially prominent among discretionary day traders who look to profit from small intraday price movements. For these traders, the speed of their decision making is often a critical factor if they are to be successful. They might describe their approach as having a "knack" for the market or a "feel" for the direction of the market.
Left-brain traders know exactly why they put on certain trades. They generally have a very specific set of criteria that must be met before they initiate a trade. In contrast, purist right-brained traders, who use their intuition almost exclusively, often don't understand exactly why they make certain trades; they just know when a trade feels right. This willingness to relinquish decision making to intuition or gut characterizes the hard-core right-brain trader.
System traders are most often left-brain dominant. They use a rational, systematic process to decide when to make trades. They often analyze their approach using computers to perform "what-if" analyses using historical data to determine the hypothetical results their trading methods might have earned in the past, a process known as backtesting. Left-brain traders don't trade on their gut or intuition; they trade using rules and strategies. These traders often think in terms of signals and triggers, as specific events that determine when to initiate a particular trade. Systems traders will have identified these specific criteria earlier, when they performed their backtesting and historical analyses.