Market mechanics
Futures margin: initial, maintenance and intraday requirements
Futures margin is collateral required to open and maintain a position. Initial margin sets the opening requirement; maintenance sets the ongoing threshold. A broker's lower intraday rate applies only under its stated conditions.
Margin is separate from the contract's value
In a live futures brokerage account, margin is a performance bond supporting the position. It is not a down payment toward owning the underlying asset or a loan to buy it. Posting margin does not cap your loss: losses can exceed the amount initially deposited.
For example, assume an E-mini S&P 500 futures contract trades at 5,000 index points. Its $50-per-point multiplier makes its notional exposure 5,000 × $50 = $250,000. A 10-point move changes a one-contract position by $500 before costs. Those amounts do not shrink because a broker permits a smaller margin deposit; 5,000 is an illustration, not a current market quote.
Sources: Schwab: futures exposure and margin mechanics · CME: performance bonds and account calculations
Read the right requirement for the position
CME Clearing sets exchange margin requirements, while a broker can require additional funds. Use the requirement applicable to your broker, contract, position and trading window rather than copying an exchange figure or another trader's rate.
| Requirement | What it governs | What to check |
|---|---|---|
| Initial | Funds required to initiate the position. | The broker's current opening and carry requirements. |
| Maintenance | The minimum margin equity required while the position is held. | The threshold and the broker's action if equity falls below it. |
| Intraday / day | A broker's reduced requirement during an eligible trading window, where offered. | Eligible products, cutoff time and temporary increases. |
Sources: CME: initial margin, maintenance and margin-call outcomes · NinjaTrader: margin and position-management policy
A margin call restores initial margin
Assume two identical outright contracts, $1,200 initial margin and $1,000 maintenance margin per contract, no other positions or offsets, and $2,800 of account equity after opening costs. These are hypothetical requirements, not current exchange or broker rates. Keep the requirements unchanged for this example.
| Step | Calculation | Result |
|---|---|---|
| Opening requirement | 2 × $1,200 | $2,400; equity exceeds it by $400. |
| Maintenance threshold | 2 × $1,000 | $2,000. |
| After a $900 loss, including costs | $2,800 − $900 | $1,900; below maintenance. |
| Funds needed to restore initial margin | $2,400 − $1,900 | $500, not the $100 maintenance shortfall. |
Sources: CME: performance bonds and account calculations · CME: initial margin, maintenance and margin-call outcomes
Do not assume a margin call gives you time
The $500 calculation describes a top-up if the broker allows the position to remain open and equity has not changed again. It is not a promised grace period. CME explains that falling below maintenance can lead to an immediate funding demand, a reduction in position size, or automatic liquidation.
A margin deficit can also arise without a new trading loss. If the required margin rises from $2,400 to $3,000 while equity stays at $2,800, the account is $200 short of the new requirement. Margin requirements can change with market risk; check the effective time as well as the amount.
Sources: CME: initial margin, maintenance and margin-call outcomes
Check the cutoff before carrying a day trade
A lower intraday margin does not grant permission to hold through every session break. NinjaTrader's published policy, checked November 6, 2026, applies intraday rates from the product open until 15 minutes before the session close, when initial margin is required. Its policy also addresses early holiday closes and sessions spanning multiple days. This is that broker's policy, not a universal cutoff.
Before carrying a position, check the product's session close and time zone, the broker's earlier margin deadline, and the requirement for the quantity you will still hold. NinjaTrader also reserves the right to change intraday requirements without prior notice and may raise entry requirements around specified economic releases. An advertised day rate alone is insufficient for this decision.
Sources: NinjaTrader: margin and position-management policy · NinjaTrader: margin requirements by market
A prop-account loss limit is a different rule
Boxcar evaluations and simulated-funded accounts use virtual funds; their orders do not enter live markets. Their displayed account size and permitted loss room are not a personal brokerage margin deposit. A brokerage top-up calculation therefore does not explain whether a simulated account has breached its rules.
Boxcar live trading uses company capital through the designated brokerage provider under a separate live agreement. Confirm those terms instead of carrying simulated-account permissions or a retail broker's advertised day margin into the live account.
Sources: Boxcar: evaluation, simulated-funded and live stages