Daily loss limits are typically 2% to 5% of the account. Some firms measure from the previous day's closing balance; others include open profit at the start of the day, which makes the limit tighter than it looks.
Hitting the limit usually ends the evaluation or funded account, not just the day. Personal traders often adopt a similar rule voluntarily.
Example: $100,000 account with a $2,500 daily limit. You are up $1,500 by 10 a.m. and then give back $4,000: you are down $2,500 net and breached, even though the total loss from the peak was larger.
Related: trailing-drawdown, max-drawdown, prop-firm, risk-management