Futures margin is not a down payment and not a loan. It is a performance bond: money you deposit to show you can cover daily losses. Because the deposit is small compared with the contract value, futures are leveraged – which is exactly why understanding margin matters.
Initial and maintenance margin
- Initial margin – what you need in your account to open a position.
- Maintenance margin – the minimum your account must keep while the position is open. If losses push your account below it, you get a margin call and must add funds or reduce the position – often your broker will close it for you.
Futures accounts are settled every day (marked to market): gains are credited and losses debited each evening. Margin is therefore checked daily, not just when you close a trade.
Exchange margin vs. broker margin
The exchange's clearing house – CME Clearing or ICE Clear U.S. – sets the minimum margin for every contract. That is the figure shown on each FuturesSpecs contract page. Your broker must collect at least that amount for positions held overnight and may ask for more.
Many brokers offer much lower day-trading margins for positions opened and closed within the same session. They are a broker decision, not an exchange rule, and they switch back to the full exchange margin if you are still in the trade at the session close.
Why long and short margins can differ
CME has moved many products to its newer margin model, which calculates the risk of long and short positions separately. For stock indexes and energy you will therefore often see two numbers. The current E-mini S&P 500 (ES) margin for ESZ26 is $26,117 long and $23,333 short (as of Sep 29, 2026). Margins also differ by contract month.
How much leverage is that?
Assume ES trades at 6,650. One contract then controls $332,500 of stocks (6,650 × $50). With a maintenance margin of $26,117, the deposit is about 7.9% of the contract value – roughly 13:1 leverage. A 1% move in the S&P 500 changes the account by about $3,325, around 13% of the margin.
The Micro E-mini S&P 500 (MES) is one tenth of that: margin $2,612 long, 1% move ≈ $332.
When margins change
Exchanges raise margins when volatility rises and lower them when markets calm down – without a fixed schedule. CME and ICE publish each change a few days in advance in their clearing advisories. FuturesSpecs shows the date of the margin figures on every page and warns when they are more than three months old.
Practical rules
- Size positions by the distance to your stop and the tick value – not by how many contracts the margin allows.
- Keep a buffer well above maintenance margin, especially before weekends and major data releases.
- Know whether you are on day-trading or overnight margin at the session close.
Educational content only – not investment advice. Futures trading involves substantial risk of loss.