For experienced traders, a safe and typical risk level is 1 % to 2 % of account equity per trade. (morpheustrading.com)
Stock brokers can require a minimum account equity of $ 25,000 to $ 100,000 for level five option trading authorization. (pocketsense.com)
Although the margin call feature is designed to close positions when account equity falls below the margin requirements, there may be instances when liquidity does not exist at the exact margin call rate. (fxcm.com)