In a margin account, a margin call can occur when the value of the account drops to a certain level, triggering a margin call. Some traders/investors borrow funds from a broker for investments. The broker loans the funds at a certain interest rate. Borrowing money on margin is called using leverage. Using leverage is a double-edged sword — while it can boost an investor’s returns and can also multiply their losses.
As an example, a trader has $10k in cash and borrows $10k from his broker to take a position in XYZ that is worth $20k. The trader is using 50% margin. XYZ’s stock price proceeds to immediately fall, leaving the trader with an account value of only $12k. The trader has $2k in equity and a $10k loan. However, his broker has a minimum margin requirement of 25%. 25% x $12k = $3k, which means, the trader should have $3k in equity for the position but only has $2k. The trader will receive a $1k margin call to bring his equity back up to 25%.