What Is a Margin Account?
Most people open a brokerage account and never think twice about the account type. But there’s a second kind that lets you borrow money to invest, and understanding the difference matters before you ever click a button.
The short answer
A margin account is a brokerage account that lets an investor borrow money from the brokerage firm, using the securities already in the account as collateral, to buy additional investments. It’s different from a standard cash account, where you can only buy what you’ve actually deposited. Margin can amplify both gains and losses, and it comes with interest costs and rules that a cash account doesn’t have.
How a margin account works
When you open a margin account, the brokerage extends you a line of credit tied to the value of the securities you hold. If you have a certain amount in eligible investments, the firm will typically let you borrow a portion of that value to purchase more shares. The securities in the account serve as collateral for the loan, similar in spirit to how a car serves as collateral for an auto loan.
The amount you’re allowed to borrow is called your buying power, and it’s usually larger than your actual cash balance because it includes the borrowed portion. That extra buying power is the whole appeal of a margin account — it lets an investor control a larger position than their cash alone would allow.
Interest and account requirements
Borrowed money isn’t free. Margin loans accrue interest, usually calculated daily and charged monthly, and the rate is set by the brokerage rather than fixed by law. That interest keeps accruing whether the investments go up or down, which is an important detail people sometimes overlook.
Margin accounts also come with minimum equity requirements, meaning you generally need to maintain a certain level of your own money in the account relative to what you’ve borrowed. If the value of your holdings drops and that cushion shrinks too far, the brokerage can issue what’s called a margin call, requiring you to add cash or sell holdings to bring the account back into line. This is one of the core risks of buying on margin, and it can force decisions at exactly the moment the market has moved against you.
Margin vs. a cash account
In a cash account, your losses are capped at the amount you invested, since you can’t spend money you don’t have. In a margin account, losses can exceed your original investment because you’re on the hook for the borrowed portion regardless of how the investments perform. This is the central trade-off: margin can increase potential returns, but it increases potential losses by the same mechanism, and it adds an ongoing interest cost on top.
Because of this asymmetry, margin accounts require an application and approval process, and brokerages typically restrict them to investors who acknowledge and accept the added risk. It’s worth thinking of margin less as a feature of “how you invest” and more as a separate financial decision layered on top of investing — closer to taking out a loan than to simply buying an index fund with your own savings.
What to weigh
A margin account isn’t inherently reckless, but it changes the nature of the risk you’re taking on. Before considering one, it helps to understand exactly how buying power, interest, and margin calls interact, and to be honest about how a sudden downturn — and a sudden bill for it — would actually feel. For many long-term investors, a standard cash account covers everything they need without introducing borrowed money into the mix at all.