All lessons
🎚️Intermediate

Position Sizing

How much to bet — and why it matters more than stock picking

Position sizing determines how much of your portfolio goes into each trade. A common rule: don't put more than 5–10% in any single stock. Even if you're right 60% of the time, a single 50% position that goes to zero can wipe out years of gains. Kelly Criterion and fixed-percentage rules help ensure no single bet can permanently damage your portfolio.

Quick check

Why does position sizing matter even if you're a good stock picker?