Discipline is the ability to follow your trading plan consistently, even when emotions say to do something different.
Your brain is wired for survival (fear) and reproduction (greed). These emotions override your logical trading plan.
Fear says: "Get out now, don't lose more"
Logic says: "Hold, your plan says hold"
Greed says: "Hold for more profit"
Logic says: "Exit at target, move to next trade"
Write It Down: Your trading plan on paper/screen. Before you trade.
Stick to It: When emotions fight, refer to your written plan. Don't improvise.
No Exceptions: If the plan says exit at $150, exit at $150. Not $151, not $149.
Review Decisions: After each trade, review. Did you follow the plan?
Small Positions: Trade small enough that emotion doesn't hijack you.
The best traders are not the smartest. They're the most disciplined. They follow their plan when everyone else is panicking.
Related: Trading Plan, Revenge Trading, Fear & Greed