Futures margin is collateral supporting a leveraged position. It is not the purchase price of the underlying asset and is not a maximum-loss limit. An account can satisfy margin when a trade opens and become under-margined after losses or a requirement change.

CME's margin lesson explains the distinction between initial and maintenance requirements.

Initial and maintenance margin

Initial margin is the amount required to establish the position under the applicable schedule. Maintenance margin is the equity threshold for continuing to carry it. Exchange/clearing requirements and a broker's additional requirements must be distinguished; the broker may require more.

Do not assume a permanent maintenance-to-initial percentage or use an undated dollar table. Requirements vary with the product and risk conditions, and brokers can change their own controls.

A futures performance bond is not a securities purchase loan. That does not mean the account has no financing economics or charges: contract pricing, cash balances, currency conversions and debit arrangements may still matter under the broker's terms.

Intraday concessions

Some brokers offer lower requirements during defined hours. The schedule can depend on contract, events, account or risk policy. There is no universal fifteen-minute-before-close cutoff and no assurance that all providers offer the same concession.

Read what happens when the concession ends. The broker may require additional funds or liquidate exposure, potentially without prior notice. Do not plan to wait until the next market open to resolve an unmet requirement.

Worked example: margin capacity is not risk capacity

Suppose a hypothetical broker requires $1,000 per contract during a session and an account holds $10,000. Ten contracts would consume the entire stated requirement before costs.

An adverse $100 move per contract produces a $1,000 loss, leaving $9,000 against the unchanged $10,000 requirement. The account is under-margined. The example demonstrates why maximum permitted size leaves no room; it is not a recommendation to trade a particular fraction of available margin.

Loss-based sizing is a separate calculation using the strategy, price distance, tick value, quantity and execution assumptions. A stop can reduce exposure when executed, but does not guarantee its fill or prevent a margin call.

Changing requirements and liquidation

Both market losses and higher requirements can create a shortfall. Check the broker's rights, how notices are delivered, deadlines and liquidation costs. A forced close can occur at an unfavourable price, and a deficit can remain afterwards.

Trading intraday does not make requirement changes irrelevant. A broker can withdraw a concession or impose an event-related increase during the session. Maintain an operational plan for reducing positions without relying on an assurance that the platform will protect the balance.

Prop rules are a different layer

A simulated evaluation's daily loss, trailing floor and contract cap are contractual programme controls. They are not exchange margin and do not replace actual exchange/broker requirements for a live account.

Topstep's overview separates simulated and live stages. Model the current stage's controls as written. Do not assume every prop programme has a daily limit or that an order-entry check can prevent every future loss breach.

What to record before trading

Save the contract and month, current margin schedule, intraday window and timezone, house overlays, liquidation policy and available cash. Separately calculate the planned loss and an adverse execution scenario.

Use the contract-specification guide for tick and multiplier arithmetic. Margin answers whether exposure is permitted under current requirements; it does not answer whether the trade is affordable or sensible.

Risk Disclaimer: Trading involves substantial risk of loss. Past performance is not indicative of future results. See our full risk disclaimer.