Margin investing means borrowing money from your broker to buy more stock than you could pay for in cash

When you buy stock on margin, your broker lends you part of the purchase price. You put down your own money — called the margin — and the broker covers the rest. If the stock price rises, your profit is larger because you controlled more shares. If the stock price falls, your loss is also larger, and you may owe the broker money even after selling.

Margin accounts are different from regular cash accounts. In a cash account, you can only buy what you have money for. In a margin account, you can borrow up to a set percentage of the purchase price, typically 50 percent under current federal rules. That means you could put down $5,000 and borrow $5,000 to buy $10,000 worth of stock.

The broker charges interest on the borrowed money, similar to a loan. The interest rate varies by broker and by how much you borrow. You pay this interest whether the stock goes up or down.

Key Takeaways

  • Margin lets you borrow money from your broker to buy more stock than you could afford with cash alone, which magnifies both gains and losses.
  • Federal rules currently allow you to borrow up to 50 percent of a stock purchase, but your broker may set stricter limits.
  • You pay interest on the borrowed amount, and that interest accrues whether your investment makes money or loses it.
  • If your stock value drops below a certain level, your broker can force you to sell holdings or deposit more cash to cover the loan — called a margin call.
  • Margin investing is riskier than buying stock with cash and is not suitable for most beginning investors.

How the math works: gains and losses on margin

Suppose you have $5,000 in cash and want to buy a stock trading at $50 per share. With cash alone, you could buy 100 shares. With a margin account, you could borrow $5,000 and buy 200 shares instead.

If the stock rises to $60 per share, your 200 shares are now worth $12,000. You owe the broker $5,000 plus interest. Your profit is roughly $7,000 minus the interest you paid — much larger than the $1,000 profit you would have made with 100 shares. But if the stock falls to $40 per share, your 200 shares are worth $8,000. You still owe the broker $5,000 plus interest. Your loss is roughly $3,000 plus interest — three times worse than the $1,000 loss you would have taken with 100 shares.

The interest cost matters. If you borrow $5,000 for a year at 8 percent annual interest, you pay $400 in interest alone. That $400 comes out of any profit you make, or adds to any loss.

Margin calls: when your broker forces action

Your broker sets a maintenance requirement — the minimum amount of your own money that must stay in the account at all times. This is usually 25 to 30 percent of the total value of your holdings. If your account value drops below that level because your stock prices fell, your broker issues a margin call.

A margin call means you must either deposit more cash into the account or sell some holdings to pay down the loan. You typically have a few days to respond, though brokers can demand payment immediately in fast-moving markets. If you do not respond, your broker can sell your holdings without asking you, often at the worst possible time.

Using the earlier example: you bought 200 shares at $50 with $5,000 of your own money and $5,000 borrowed. If the stock falls to $37.50 per share, your holdings are worth $7,500. Your loan is still $5,000, so your equity is $2,500. That is 33 percent of the account value — still above the typical 25 percent minimum. But if the stock falls to $35, your holdings are worth $7,000, your equity is $2,000, and that is 29 percent — still okay. At $33 per share, your holdings are worth $6,600, your equity is $1,600, and that is 24 percent — below the 30 percent threshold. Your broker issues a margin call.

Interest rates and borrowing costs

Margin interest rates vary widely. Large brokers typically charge between 6 and 12 percent annually, depending on how much you borrow and current market conditions. Some brokers offer lower rates to customers with large accounts. The rate can change at any time.

Interest accrues daily and is usually charged monthly to your account. If you borrow $10,000 at 8 percent for one month, you owe roughly $67 in interest. That amount is deducted from any cash in your account or added to your loan balance.

Over time, margin interest can eat significantly into returns. A stock that gains 10 percent in a year may only net you 2 percent after paying 8 percent in margin interest on borrowed money.

Who can open a margin account and what brokers require

Most brokers require you to have a minimum account balance — often $2,000 to $5,000 — before opening a margin account. You must also pass a background check and sign a margin agreement that explains the risks and terms.

Some brokers restrict margin accounts for new investors or those under 18. A few brokers do not offer margin at all. You choose whether to open a margin account when you set up your brokerage account; you do not have to use it immediately.

Once your margin account is open, you can choose to buy individual stocks on margin or with cash. You do not have to use margin for every purchase.

Risks specific to margin investing

Margin amplifies losses in ways that cash investing does not. You can lose more money than you invested. If you borrow $5,000 and the stock becomes worthless, you still owe the broker $5,000 plus interest, even though your shares are worth zero.

Margin calls can force you to sell at the worst time. If your stock drops sharply and you receive a margin call, you may have to sell holdings at a loss to raise cash, locking in losses you might have recovered if you held longer.

Margin interest is a cost you pay regardless of performance. Even if your stock does not move, you are paying interest on the borrowed money. This makes margin more suitable for active traders who expect to profit quickly, not for long-term buy-and-hold investors.

Frequently Asked Questions

Can I lose more money than I invested with margin?

Yes. If you invest $5,000 of your own money and borrow $5,000, you control $10,000 in stock. If that stock drops 80 percent, it is worth $2,000. You still owe the broker $5,000 plus interest, so you have lost your entire $5,000 and owe an additional $3,000 out of pocket.

What happens if I cannot pay a margin call?

Your broker will sell your holdings without your permission to raise enough cash to cover the loan. They typically sell whatever is easiest to sell, not necessarily what you would choose to sell. You may end up with a loss and no way to recover if the stock rebounds later.

Is margin the same as day trading?

No. Margin is borrowing money to buy stock. Day trading is buying and selling the same stock within one day. You can day trade without margin (using only cash) or use margin for longer-term positions. However, day traders often use margin to control larger positions.

Do I have to use margin if I open a margin account?

No. Opening a margin account gives you the option to borrow, but you can buy all your stock with cash if you choose. Many investors open margin accounts but rarely or never use them.

What is the difference between margin and a loan?

A margin loan is secured by the stock you buy — your broker can sell your holdings if you do not repay. A personal loan is unsecured and typically has a fixed repayment schedule. Margin interest rates are usually lower than personal loan rates, but margin loans can be called due immediately if your account value drops.