To engage in margin trading, an investor must first open a specialized . This process is governed by specific regulatory and institutional rules designed to manage credit risk: What is Buying on Margin? - Robinhood

The Double-Edged Sword: Understanding Buying on Margin Buying on margin is the financial practice of purchasing securities using a combination of an investor’s own cash and funds borrowed from a brokerage firm. In this arrangement, the investor’s existing portfolio and the newly purchased shares serve as collateral for the loan. While this strategy offers a powerful mechanism to amplify potential returns, it equally magnifies the risk of devastating losses, making it a "double-edged sword" in the world of investing. The Mechanics of Margin Trading