For the 1-step and 2-step funding models:
There is no lot size restriction on any of our challenge models including the challenge accounts as well as challenge simulated funded accounts.
For Instant Funding accounts:
For $25,000 Instant account: Maximum 2 lots per trade on forex pairs, there is no limit on gold.
For $50,000 Instant account: Maximum 4 lots per trade on forex pairs, there is no limit on gold.
For example, on instant funding accounts, you can open 2 lots on EUR/USD pair on a $25,000 account and open another trade at a same time with 2 lot if leverage allows but on a different pair e.g, GBP/USD.
Lot restriction is only for one pair at one time.