What Is Margin?

Margin is the money borrowed from a brokerage firm to purchase an investment. It is the difference between the total value of securities held in an investor's account and the loan amount from the broker. Buying on margin is the act of borrowing money to buy securities. The practice includes buying an asset where the buyer pays only a percentage of the asset's value and borrows the rest from the bank or broker. The broker acts as a lender and the securities in the investor's account act as collateral.

In a general business context, the margin is the difference between a product or service's selling price and the cost of production, or the ratio of profit to revenue. A margin can also refer to the portion of the interest rate on an adjustable-rate mortgage (ARM) added to the adjustment-index rate.

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Margin

Understanding Margin

A margin refers to the amount of equity an investor has in their brokerage account. "To margin" or "to buy on margin" means to use money borrowed from a broker to purchase securities. You must have a margin account to do so, rather than a standard brokerage account. A margin account is a brokerage account in which the broker lends the investor money to buy more securities than what they could otherwise buy with the balance in their account.

Using margin to purchase securities is effectively like using the current cash or securities already in your account as collateral for a loan. The collateralized loan comes with a periodic interest rate that must be paid. The investor is using borrowed money, or leverage, and therefore both the losses and gains will be magnified as a result. Margin investing can be advantageous in cases where the investor anticipates earning a higher rate of return on the investment than what he is paying in interest on the loan.

For example, if you have an initial margin requirement of 60% for your margin account, and you want to purchase $10,000 worth of securities, then your margin would be $6,000, and you could borrow the rest from the broker.

Key Takeaways

  • Margin refers to money borrowed from a brokerage to trade securities.
  • Margin trading therefore refers to the practice of using borrowed funds from a broker to trade a financial asset, which forms the collateral for the loan from the broker.
  • A margin account is a standard brokerage account in which an investor is allowed to use the current cash or securities in their account as collateral for a loan.
  • The collateralized loan comes with a periodic interest rate that the investor must repay to the broker.
  • Leverage conferred by margin will tend to amplify both gains and losses. In the event of a loss, a margin call may require your broker to liquidate securities without prior consent.

Buying on Margin

Buying on margin is borrowing money from a broker in order to purchase stock. You can think of it as a loan from your brokerage. Margin trading allows you to buy more stock than you'd be able to normally. To trade on margin, you need a margin account. This is different from a regular cash account, in which you trade using the money in the account.

By law, your broker is required to obtain your consent to open a margin account. The margin account may be part of your standard account opening agreement or may be a completely separate agreement. An initial investment of at least $2,000 is required for a margin account, though some brokerages require more. This deposit is known as the minimum margin. Once the account is opened and operational, you can borrow up to 50% of the purchase price of a stock. This portion of the purchase price that you deposit is known as the initial margin. It's essential to know that you don't have to margin all the way up to 50%. You can borrow less, say 10% or 25%. Be aware that some brokerages require you to deposit more than 50% of the purchase price. (Related: Buying on Margin Explainer Video)

You can keep your loan as long as you want, provided you fulfill your obligations such as paying interest on time on the borrowed funds. When you sell the stock in a margin account, the proceeds go to your broker against the repayment of the loan until it is fully paid. There is also a restriction called the maintenance margin, which is the minimum account balance you must maintain before your broker will force you to deposit more funds or sell stock to pay down your loan. When this happens, it's known as a margin call. A margin call is effectively a demand from your brokerage for you to add money to your account or close out positions to bring your account back to the required level. If you do not meet the margin call, your brokerage firm can close out any open positions in order to bring the account back up to the minimum value. Your brokerage firm can do this without your approval and can choose which position(s) to liquidate. In addition, your brokerage firm can charge you a commission for the transaction(s). You are responsible for any losses sustained during this process, and your brokerage firm may liquidate enough shares or contracts to exceed the initial margin requirement.

Special Considerations

Borrowing money isn't without its costs. Indeed, marginable securities in the account are collateral. You'll also have to pay the interest on your loan. The interest charges are applied to your account unless you decide to make payments. Over time, your debt level increases as interest charges accrue against you. As debt increases, the interest charges increase, and so on. Therefore, buying on margin is mainly used for short-term investments. The longer you hold an investment, the greater the return that is needed to break even. If you hold an investment on margin for a long period of time, the odds that you will make a profit are stacked against you.

Not all stocks qualify to be bought on margin. The Federal Reserve Board regulates which stocks are marginable. As a rule of thumb, brokers will not allow customers to purchase penny stocks, over-the-counter Bulletin Board (OTCBB) securities or initial public offerings (IPOs) on margin because of the day-to-day risks involved with these types of stocks. Individual brokerages can also decide not to margin certain stocks, so check with them to see what restrictions exist on your margin account.

A Buying Power Example

Let's say that you deposit $10,000 in your margin account. Because you put up 50% of the purchase price, this means you have $20,000 worth of buying power. Then, if you buy $5,000 worth of stock, you still have $15,000 in buying power remaining. You have enough cash to cover this transaction and haven't tapped into your margin. You start borrowing the money only when you buy securities worth more than $10,000. 

This brings us to an important point: the buying power of a margin account changes daily depending on the price movement of the marginable securities in the account. Later in the tutorial, we'll go over what happens when securities rise or fall.

Other Uses of Margin

Accounting Margin

In business accounting, a margin refers to the difference between revenue and expenses, where businesses typically track their gross profit margins, operating margins, and net profit margins.

The gross profit margin measures the relationship between a company's revenues and the cost of goods sold (COGS). Operating profit margin takes into account COGS and operating expenses and compares them with revenue, and net profit margin takes all these expenses, taxes and interest into account.

Margin in Mortgage Lending

Adjustable-rate mortgages offer a fixed interest rate for an introductory period of time, and then the rate adjusts. To determine the new rate, the bank adds a margin to an established index. In most cases, the margin stays the same throughout the life of the loan, but the index rate changes.

To understand this more clearly, imagine a mortgage with an adjustable rate has a margin of 4% and is indexed to the Treasury Index. If the Treasury Index is 6%, the interest rate on the mortgage is the 6% index rate plus the 4% margin, or 10%.