A buffer is a slice of your shown profit that a firm holds back when it works out what you may withdraw. Your dashboard may show $2,000 in profit while only $1,500 counts toward a payout request, because $500 is held as a buffer. The buffer is not a fee and it is not lost forever; it is a cushion the firm keeps against later losses before it releases the rest.
Buffers take different forms. Some firms hold back a fixed part of shown profit on certain plans. Others tie the buffer to a risk number: BEM Funding's One Only plan, for example, keeps at least half the daily drawdown amount as a buffer. The firms we track also include plans where part of shown profit is held as a buffer without a fixed figure published.
This matters because the buffer decides what a payout request actually pays. A trader who plans spending around the dashboard profit will be short by the buffer amount, and a trader who requests the full shown profit will have the request cut down.
The common trap is treating dashboard profit as withdrawable cash. We recommend checking the payout page for a buffer rule before you count any profit as money in hand. Prop trading can cost you every fee you pay.