Margin Trading

"Margin" trading is borrowing money from your broker to buy a stock and using your investment as collateral. Investors generally use margin to increase their purchasing power so that they can own more stock without fully paying for it. But margin exposes investors to the potential for higher losses. Here's what you need to know about margin.

Let's say you buy a stock for $50 and the price of the stock rises to $75. If you bought the stock in a cash account and paid for it in full, you'll earn a 50 percent return on your investment. But if you bought the stock on margin — paying $25 in cash and borrowing $25 from your broker — you'll earn a 100 percent return on the money you invested. Of course, you'll still owe your firm $25 plus interest.

The downside to using margin is that if the stock price decreases, substantial losses can mount quickly. For example, let's say the stock you bought for $50 falls to $25. If you fully paid for the stock, you'll lose 50 percent of your money. But if you bought on margin, you'll lose 100 percent, and you still must come up with the interest you owe on the loan.

In volatile markets, investors who put up an initial margin payment for a stock may, from time to time, be required to provide additional cash if the price of the stock falls. Some investors have been shocked to find out that the brokerage firm has the right to sell their securities that were bought on margin — without any notification and potentially at a substantial loss to the investor. If your broker sells your stock after the price has plummeted, then you've lost out on the chance to recoup your losses if the market bounces back.