Britannica Money (2024)

Margin is used by different types of traders and investors in different ways. Trading on margin (aka trading with leverage) can help traders juice their buying power and potentially amplify returns (or accelerate losses). But in the financial markets, one form of leverage is not like another.

Margin is akin to a mechanic’s wrench—a simple but powerful tool for doing more with less. Just as any mechanic’s toolbox holds different types and sizes of wrenches for different needs, so it is with margin. The world’s vast and complex financial system turns on a variety of lug nuts leveraged by an assortment of margin varieties used by different types and sizes of traders and investors.

Let’s begin by looking at three primary categories of margin:

• Regulation T (aka Reg T) margin. Gives you up to double the buying power for stocks and other securities.
• Futures margin. Your “good faith” deposit covers a percentage of losses; can offer a tenfold increase in buying power (or more).
• Portfolio margin. A formulaic approach to margin based on the overall risk of a position. Typically the realm of active traders with many portfolio components.

What is Reg T margin?

Probably the most commonly known version of margin, “Reg T” refers to the Federal Reserve’s Regulation T, which was part of the 1934 Securities Exchange Act. Under Reg T, investors can borrow up to 50% of the purchase price of securities. This is also known as “initial” margin. (Brokerages can establish their own margin requirements, but they must be at least as restrictive as Reg T.)

Under Reg T, an investor who is approved to trade with a margin account could, for example, take $10,000 in cash and buy $20,000 worth of stock. That doubles the risk, but also doubles the potential return. (Read a detailed example here.) And remember: margin loans, like any loan, must be paid back, with interest.

What is futures margin?

Margin in futures markets differs from equities margin in a few important ways. With futures, traders must put down a good-faith, initial margin requirement, also known as a “performance bond,” which ensures each party (the buyer and the seller) can meet their obligations as spelled out in the futures contract.

Initial margin requirements vary depending on the commodity or financial product, but are typically just a fraction of what equity investors might pony up—maybe 2% to 12% of the “notional” value of the contract (the cash equivalent value of owning the asset, or the total value of the contract).

Futures trading also requires maintenance margin, which is a certain amount of money that must be maintained on deposit with the futures broker. If the money in your account falls below the maintenance margin level, you’ll be issued a margin call, and you’ll be required to add funds to your account, typically enough to bring the account back up to the initial margin level.

For example, one Micro WTI Crude Oil futures contract traded with CME Group, which represents 100 barrels of the U.S. benchmark West Texas Intermediate grade crude, had an initial margin of $930 and maintenance margin of $750 in late 2022. At the oil market price of $80 per barrel (at the time), that $930 margin represented about 11.6% of the contract’s notional value ($80 x 100 = $8,000; $930 / $8,000 = 11.6%).

What is portfolio margin?

Portfolio margin is designed for more active, and often bigger, traders—people or firms that hold many margined positions across different asset classes, such as stocks, bonds, futures, and foreign currencies. Portfolio margin often requires “permission” or other forms of approval from a broker, as well as a certain amount of money (or “minimum equity requirements”—some brokers require at least $100,000).

In theory, portfolio margin benefits both the trader and the broker/lender. It provides a holistic, consolidated assessment of risks and exposure for the lender (plus, more fee revenue). At the same time, it offers greater flexibility and lower margin costs for the trader (as opposed to treating every margined position as a separate transaction).

The rationale behind portfolio margin is simple: Because the broker and/or clearinghouse holds your positions and money and keeps track of the account values, it’s ultimately on the hook if your account becomes deficient. They require you to post (and maintain) margin as a cushion or “head start” in case your account value starts going the wrong way.

So, if you have positions that might—from a total risk standpoint—cancel each other out to some degree, the broker might not require total margin for each position. For example, maybe you bought a bunch of stocks or exchange-traded funds (ETFs) on margin, but sold a stock index futures contract—or you hold offsetting options contracts—and you meet the portfolio margin requirements. Your broker might assess your margin based on its portfolio risk formula, which essentially stress-tests your portfolio in a variety of market scenarios.

The bottom line

Whatever type of trader you are or the type of leverage you might use, it’s important to remember that margin is ultimately other people’s money loaned to you, and it must be paid back. Whether you’re a retail trader buying or selling a few dozen or a few hundred shares, or a high-rolling hedge fund manager overseeing an alphabet soup of positions worth millions or billions of dollars, using margin can be a useful but risky tool. Margin carries considerable potential rewards, but also potentially ruinous consequences. Borrower, beware.

References

• Portfolio Margin FAQ | finra.org
• Investing with Borrowed Funds: No “Margin” for Error | finra.org
• OCC: Portfolio Margin Calculator | theocc.com
• Performance Bonds/Margins FAQ | cmegroup.com