How to size positions for a 100K funded account

On a 100K account, the drawdown limit is a fixed dollar amount you cannot touch. That number — not your profit target — is the input to every sizing decision. The question is never “how big can I go to hit the target fast?” It's “how big can I go and still survive my worst realistic losing streak?”

Start from the floor, work backwards

Take the maximum drawdown. Decide how many consecutive full-stop losses you must be able to absorb without breaching it — not the average streak, the bad-tail streak. Divide accordingly. That gives you a per-trade risk, and from there a position size. The target is then just a function of time, not something you size toward.

Size against the bad tail, not the median

This is where Monte Carlo earns its keep. Sizing so the median outcome looks great but the P10 sequence breaches the floor is a strategy that works until the first unlucky run ends it. Size so the P10 path survives, and the median becomes pure upside. The balanced 100K configuration above is sized exactly this way — the steady curve is the visible result of a conservative size against the floor.

Don't resize after a good run

The most common funded-account mistake is increasing size after a winning streak, right when the account feels invincible. That converts a survivable strategy into a fragile one at the worst moment. Keep the size derived from the floor, let profits accumulate, and let blow rate stay where you set it.