Max Position Size and Micros

Max Position Size
The max position size is the max number of contracts allowed at any given time – i.e. if you have a max position size of 3 contracts, you can be long 2 YM and short 1 ES. If you go over the number of contracts allowed, the system will reject the orders which exceed the number of contracts allowed.  

Micros are active and included with both Evaluation and Performance Accounts.  You are allowed to trade up to 10x the number of Micro future contracts as your standard lot max contract limit on your account.  I.e.  If you are in a 3 max contract account... you can trade up to 30 Micros.  If you have an 8 contract max account... you can trade up to 80 Micros.