Negative Balance Protection
A guarantee that you cannot lose more than the money in your trading account.
In a violent market move, prices can gap straight through your stop-loss and the broker's stop-out level. Without protection, that leaves the account below zero and you owing the broker money - exactly what happened to thousands of traders during the 2015 Swiss franc de-pegging.
Negative balance protection caps your maximum loss at your deposited funds. If a gap pushes the account negative, the broker absorbs the shortfall and resets your balance to zero. It is mandatory for retail clients under FCA, ASIC, CySEC, BaFin and other tier-one regulators.
It is not universal. Offshore-licensed entities and professional-classified accounts frequently exclude it, and the same broker brand can offer it under one licence and not another. Check which entity you are actually signing up with before assuming you are covered.