Many, many times traders are quite conscientious and self-controlled in most areas of their lives, but experience lapses of discipline specific to trading. When this happens, it’s often the case that the trading itself–*how* they’re trading–is artificially creating the failure to follow trading rules. A key culprit in all this is market volatility. Volatility changes from day to day and week to week. It also varies as a function of time of day. Frequently, traders trade a fixed size and set fixed targets and stops, heedless of the underlying market volatility. In a low volatility environment, they fail to hit their targets and get stopped out, criticizing themselves for leaving money on the table. In an environment of enhanced volatility, the market will blow through their stops or exceed their targets, leaving them feeling that they did not trade well. This is especially true when traders find themselves unable to take what is normal heat in an environment of raised volatility. In such cases, it really isn’t a lapse of discipline causing the problem. Rather, the trader is not adapting to market conditions. Adhering to fixed rules in a variable environment is not necessarily a virtue. Changing markets can prevent us from enacting those fixed rules.