Futures traders post a deposit that the CFTC describes as typically between two and 10 percent of the total value of the contract, and that deposit is a performance bond rather than a down payment. Nothing has been part-paid. The full contract value is live from the first tick, and the one figure that changes the exposure is the contract's own size, not the cash behind it.
Contract size sets the exposure
A futures contract's size is fixed by the exchange and does not move. Schwab's futures page states the standard sizes plainly: one E-mini S&P 500 contract represents $50 times the price of the S&P 500 Index, one crude oil contract represents 1,000 barrels, and one gold contract represents 100 troy ounces. Multiply the size by the current price and the result is the contract value, also called notional value.
The same broker page runs the multiplication: with the index quoted at 2,250, one E-mini contract carries $112,500 of notional value. That figure is what gains and losses are computed against. The deposit is computed against it too, which is the source of the confusion: both numbers are percentages of the same contract, but only one of them is the exposure.
Worked example: one E-mini contract
Take the broker page's own quote of 2,250 on the index. One contract is $50 times 2,250, or $112,500 of notional value. Schwab's page puts the required initial margin at 3 percent to 12 percent of the underlying contract value, so the cash to open runs from $3,375 at 3 percent to $13,500 at 12 percent.
Now move the index 1 percent, to 2,272.50 or to 2,227.50. That is 22.5 points, and at $50 a point the position gains or loses $1,125. Against a $3,375 deposit that single percent is 33.3 percent of the money posted. Against a $13,500 deposit it is 8.3 percent. The index moved once; the two accounts saw two different numbers because the deposit, not the exposure, changed between them.
The CFTC's own example uses grain. A CBOT wheat contract provides for delivery of 5,000 bushels, and with initial and maintenance margin of $650 per contract a farmer selling 10 contracts deposits $6,500. Ten contracts is 50,000 bushels of exposure standing on $6,500.
Scroll sideways to see the full table →
| Position | One unit represents | Cash required to open |
|---|---|---|
| E-mini S&P 500 futures | $50 times the index | 3 to 12 percent of contract value |
| Crude oil futures | 1,000 barrels | 3 to 12 percent of contract value |
| Marginable stock on margin | one share | 50 percent of the purchase price under Regulation T |
Why the stock comparison misleads
In a stock margin account the borrowed half is a loan. Regulation T of the Federal Reserve Board lets a broker lend up to 50 percent of the purchase price of margin securities, interest accrues on the balance, and the shares are collateral. A futures deposit is none of that. The CFTC states it directly: margins in the futures markets are not down payments like stock margins, but performance bonds that show the trader can meet the obligation.
The consequence is in the accounting. A stock position is marked in the account but settles nothing until it is sold; a futures position is marked to the market each day, with the day's loss debited from the margin account and the day's gain credited to it. If the balance falls below the maintenance level, variation margin is required to bring it back. That daily cash movement is set out in the guide on futures mark-to-market, and the ownership difference is covered in the guide on a futures position versus share ownership.
The deposit moves; the contract does not
The exchange sets the initial margin and can change it. Schwab's disclosure states that the firm can raise its own house margin requirements at any time and without advance notice, and that a customer is not entitled to an extension of time on any type of margin call. The CFTC notes the same layering from the other side: futures commission merchants often require customers to hold more in the margin account than the exchange level, and if the balance drops below the maintenance figure the trader posts variation margin to restore it.
So the deposit is the variable and the exposure is the constant. A trader who sizes a position by what the broker will accept has let someone else's risk model pick the trade size. Sizing by contract value puts the decision back where the arithmetic is.
Two figures answer the question at the start of any futures position: the contract's size and the current price. Their product is the exposure. The deposit is a separate number, set by the exchange and raised by the broker at will, and the guide on cash and margin accounts covers the equivalent split on the equity side.
Source references
Primary sources used for this guide. Follow the links for the original scope, definitions and conditions.
- Economic Purpose of Futures Markets and How They Work | CFTCAccessed 2026-09-17
- What are futures? | Charles Schwab Futures and ForexAccessed 2026-09-17
- Investor Bulletin: Understanding Margin Accounts | Investor.govAccessed 2026-09-17