How does the scaling plan work?
Your maximum position size scales up as you build closed profits and scales down as you take losses. Open, unrealized profits do not increase your contract limit. Your allowance after each closed is based on your account balance intraday after all trades are closed.
For example, $1,000 of account balance allows 1 mini / 10 micros, $2,000 allows 2 minis / 20 micros, and $4,000 allows 4 minis / 40 micros, up to a maximum of 15 minis / 150 micros.