Futures brokers quote two kinds of margin for the same contract: a low figure for positions that are closed the same day and a much higher one for positions held overnight. The difference can be large, and mixing the two up is one of the most common ways for a small account to get a position closed by force. This guide explains where each number comes from, who sets it and what to check before you rely on the low one. The basics of initial and maintenance margin are in the futures margin guide.
Two numbers, two different authors
Overnight margin is the requirement for a position that stays open through the daily settlement and the maintenance break. The minimum is set by the clearing house – CME Clearing or ICE Clear U.S. – and the broker passes it on or adds a buffer. This is the figure shown on every FuturesSpecs contract page. For the E-mini S&P 500 (ES) the maintenance margin is $26,117 long and $23,333 short (as of Sep 29, 2026); for the Micro E-mini S&P 500 (MES) it is $2,612 long.
Day-trading margin, also called intraday margin, is different in kind. It is a broker decision, not an exchange rule. The broker takes the view that a position which will be closed within the session carries less risk to the broker, and lets you open it with a fraction of the overnight amount. The fraction differs by broker, by contract and sometimes by account type, and a broker can change it without notice. Because the exchange sets no such figure, FuturesSpecs does not show one and this guide gives no numbers for it: the only reliable source is your broker's current margin table.
What “intraday” actually means
The low margin is not available around the clock. Depending on the broker, it applies from the open of the session or only during the U.S. day session, and it ends at a cutoff shortly before the close. At the cutoff the broker switches the position to the full overnight margin – many brokers ask for the exchange's initial margin, which is higher than the maintenance figure shown on this site. Two things follow from that:
- The cutoff comes before the close. Brokers often set it 15 minutes or more before the end of the session – with a 15-minute cutoff, equity index futures on CME switch at 4:45 p.m. ET, ahead of the 5:00 p.m. ET maintenance break; some brokers switch up to an hour earlier. Some brokers use a different cutoff per product. Read the exact time in your broker's rules.
- The cutoff is a margin check, not a gentle reminder. If your account holds less than the overnight margin when it passes, many brokers close the position automatically at the market. You get the price of that moment, in a market that is often thin at the end of the session, and some brokers charge a fee for the forced liquidation.
Holidays and early closes move the cutoff as well. On a shortened session the cutoff moves with the early close, so the safe habit is to be flat or fully funded well before it.
A worked example
Suppose you want to trade one E-mini S&P 500 (ES) contract with an intraday margin of $500 – a made-up figure for the arithmetic, not a quote from any broker. You deposit $1,000. The position is allowed. Now two things can go wrong:
- You hold past the cutoff. The requirement jumps from $500 to at least the overnight maintenance margin of $26,117, and many brokers ask for the higher initial margin. With $1,000 in the account you are far below it. The broker closes the position, whether it is at a profit or a loss.
- The market moves against you. One ES point is $50. A move of 10 points against you costs $500 and leaves the account at the intraday margin, so the broker can start closing the position. A gap of 20 points costs $1,000 – the whole account, even though the low margin looked like plenty of room.
The second point is the more important one. A low intraday margin does not lower the risk of the position; it only lowers the deposit the broker asks for. The contract is still worth the same amount and moves the same way. Size the position by the distance to your stop and the tick value, and treat the margin as a technical minimum.
The pattern day trader rule and futures accounts
If you come from stock trading, you may know the pattern day trader rule: a $25,000 minimum for securities margin accounts that made four or more day trades in five business days. It never applied to futures accounts. FINRA replaced it with intraday margin requirements effective June 4, 2026; brokers have until October 20, 2027 to switch, so some may still apply the old rule to stock accounts. For a futures account, what applies is the broker's own rule: a minimum deposit, the intraday margin table and the cutoff. Brokers may also set a higher margin around specific events, such as major data releases; see below.
When intraday margin disappears
Brokers can switch to the full overnight margin earlier than the usual cutoff. Typical cases are the minutes around major scheduled releases (see trading around reports) – some brokers raise the margin on stock index futures before important U.S. data and restore the normal intraday margin only afterwards – and periods of unusual volatility. Before the first position day of a physically delivered contract, brokers restrict new positions or close them (see holding past the first notice day). A broker usually announces such rules in its margin notices or the trading platform, not in the order ticket. If you rely on a small intraday margin, subscribe to those notices.
Checklist before you use the low margin
- Find the broker's intraday margin and the cutoff time for the contract you trade, and write both down.
- Check the overnight margin on the contract page or the exchange margin page, and ask yourself whether the account could carry it. If not, you must be flat before the cutoff.
- Plan the exit around the cutoff, not around the close. If a trade is still open ten minutes before it, decide to close it or to fund it.
- Keep a buffer above the margin for adverse moves. Margin is a minimum, not a loss limit; see starting capital for Micro futures.
- Look at the rules for the specific day: holidays, early closes and the broker's notices.
- If you also hold options on the same underlying, ask whether your broker still grants the intraday margin; some brokers withdraw it in that case (see futures vs. options on futures).
This guide is general information and does not describe the rules of a specific broker. Futures trading carries a high risk of loss.
Educational content only – not investment advice. Futures trading involves substantial risk of loss.