Epictetus drew a bright line between what we govern and what we don’t; investors can, too. You cannot command prices, macro surprises, or breaking news, but you can shape allocation, fees, taxes, risk limits, and behavior. Build pre-commitments, accept noise as weather, and act only where influence is real.
A thirty-second check can save a portfolio year: note hunger, anger, loneliness, tiredness, and time pressure before clicking buy or sell. Name the feeling, breathe deeply, and delay impulsive action. Record intent, alternative options, and stop-loss logic, turning hazy urges into documented, reviewable discipline.