Initial balance drawdown is one of our rules, that you must follow during the evaluation process or during the E8 Trader Stage.
If you go below the initial balance limit you will lose your account.
For example with an 8% initial balance drawdown, if you have an account with $200,000 (which is the initial balance) and your floating + closed loss exceeds the $184,000 (which is the max. initial balance limit) you will lose your challenge.
Also keep in mind, that in the E8 Trader Stage, you get to keep the balance that is snapshotted during payout as a "Scaled balance". So if your account progresses from $200,000 to $250,000, the 8% initial balance drawdown will count from $250,000 and not $200,000.