The Logic Behind Auto-Scale
Auto-Scale adjusts each copied trade's lot size in proportion to the balance difference between your account and the master trader's account, so risk stays relatively consistent regardless of account size.
Example
If the master account has $10,000 and opens a 1.0 lot trade, a follower account with $1,000 (a 10x smaller balance) would automatically copy that trade at approximately 0.10 lots.
Auto-Scale is recommended for most followers, since it removes the need to manually recalculate lot sizes as balances change.