
Bruce Blythe is a veteran financial journalist with expertise in agriculture and food production; commodity futures; energy and biofuels; investing, trading, and money management; cryptocurrencies; retail; and technology.
Doug is a Chartered Alternative Investment Analyst who spent more than 20 years as a derivatives market maker and asset manager before “reincarnating” as a financial media professional a decade ago.
Before joining Britannica, Doug spent nearly six years managing content marketing projects for a dozen clients, including The Ticker Tape, TD Ameritrade’s market news and financial education site for retail investors. He has been a CAIA charter holder since 2006, and also held a Series 3 license during his years as a derivatives specialist.
Doug previously served as Regional Director for the Chicago region of PRMIA, the Professional Risk Managers’ International Association, and he also served as editor of Intelligent Risk, PRMIA’s quarterly member newsletter. He holds a BS from the University of Illinois at Urbana-Champaign and an MBA from Illinois Institute of Technology, Stuart School of Business.

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 mechanicâs wrenchâa simple but powerful tool for doing more with less. Just as any mechanicâs toolbox holds different types and sizes of wrenches for different needs, so it is with margin. The worldâs 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.
Letâs begin by looking at three primary categories of margin:
Probably the most commonly known version of margin, âReg Tâ refers to the Federal Reserveâs 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 âinitialâ 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.
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 âperformance bond,â 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 upâmaybe 2% to 12% of the ânotionalâ 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, youâll be issued a margin call, and youâll 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 contractâs notional value ($80 x 100 = $8,000; $930 / $8,000 = 11.6%).
Learn all about futures margin and margin calls.
Portfolio margin is designed for more active, and often bigger, tradersâpeople or firms that hold many margined positions across different asset classes, such as stocks, bonds, futures, and foreign currencies. Portfolio margin often requires âpermissionâ or other forms of approval from a broker, as well as a certain amount of money (or âminimum equity requirementsââsome 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, itâs ultimately on the hook if your account becomes deficient. They require you to post (and maintain) margin as a cushion or âhead startâ in case your account value starts going the wrong way.
So, if you have positions that mightâfrom a total risk standpointâcancel 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 contractâor you hold offsetting options contractsâand 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.
Whatever type of trader you are or the type of leverage you might use, itâs important to remember that margin is ultimately other peopleâs money loaned to you, and it must be paid back. Whether youâre 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.