Margin trading is a method that allows investors to borrow money from a broker to trade larger amounts than they could with their own funds. This practice can amplify potential profits, as traders can control more assets with less capital. However, it also increases the risk, as losses can exceed the initial investment. In margin trading, investors must maintain a minimum balance, known as the margin requirement, in their account. If the account value falls below this level, the broker may issue a margin call, requiring the investor to deposit more funds or sell assets to cover the losses.