Losing discipline is not a trading problem; it is the common result of a number of trading-related problems. Here are the most common sources of loss of discipline, culled from my work with traders:

10) Environmental distractions and boredom cause a lack of focus;

9) Fatigue and mental overload create a loss of concentration;

8) Overconfidence follows a string of successes;

7) Unwillingness to accept losses, leading to alterations of trade plans after the trade has gone into the red;

6) Loss of confidence in one’s trading plan/strategy because it has not been adequately tested and battle-tested;

5) Personality traits that lead to impulsivity and low frustration tolerance in stressful situations;

4) Situational performance pressures, such as trading slumps and increased personal expenses, that change how traders trade (putting P/L ahead of making good trades);

3) Trading positions that are excessive for the account size, created exaggerated P/L swings and emotional reactions;

2) Not having a clearly defined trading plan/strategy in the first place;

1) Trading a time frame, style, or market that does not match your talents, skills, risk tolerance, and personality.