Max Position Size and Micros

Max Position Size
The max position size is the total number of contracts allowed at any given time. If you have exceeded the max contract limit in a reckless and abusive fashion, your account may be closed.  
Example of the $25,000 Aspire (3 maximum contract) practice account: 
You could open 2 long YM positions and 1 short ES position simultaneously. The total concurrent standard lot position across all instruments can be no more than 3. 
Contract limits per account type:

Micros are active and included with both practice and Leeloo Performance Accounts. You are allowed to trade up to 10x the number of Micro contracts as your standard lot max contract limit on your account.

Example of the $50,000 Launch (8 maximum contract) practice account: 
You can trade up to 80 total Micros simultaneously across all micro instruments. You could be long 50 MES, short 20 MNQ, and short 10 MGC (totaling 80) at the same time.  

Warning: Do NOT engage in any trading activity with money you cannot afford to lose. Day trading can be extremely risky and offers no guarantee for success. You should not fund day-trading activities with retirement savings, student loans, second mortgages, emergency funds, funds set aside for purposes such as education or home ownership, or funds required to meet your living expenses. 

If you engage in day trading activities, set a budget and do not spend beyond your set budget.