Browse Trading

Initial Margin

Initial margin is the equity or collateral required before a leveraged securities, futures, or derivatives position can be opened.

Initial margin is the equity, cash, or collateral required to open a leveraged position. In a securities margin account, it limits how much of a purchase can be financed with broker credit; in futures and derivatives markets, it often works as performance collateral for the contract.

Initial margin matters because it sets the starting leverage of a trade. A position that meets the opening requirement can still become unsafe later if prices move, volatility rises, or maintenance requirements change.

Key Takeaways

  • Initial margin is the opening requirement, not the ongoing maintenance requirement.
  • The requirement can come from Regulation T, FINRA or exchange rules, clearinghouse models, and broker house policy.
  • Brokers may require more than the minimum rule level.
  • Futures and derivatives margin is not always a loan; it can be collateral for contract performance.
  • Meeting initial margin does not protect against losses, margin calls, or forced liquidation.

Example

Suppose a broker requires $6,000 of investor equity to open a $12,000 stock position in a margin account. The investor may be able to finance the rest with a margin loan if the account and security are eligible.

That opening calculation does not answer what happens later. If the stock falls or the broker raises the requirement, the account may need more equity even though the initial trade was accepted.

Initial Margin vs. Maintenance Margin

FeatureInitial marginMaintenance margin
TimingChecked when opening or increasing a positionChecked after the position is open
Main purposeLimits starting leverageKeeps account equity above an ongoing threshold
TriggerNew trade, position increase, or new contractPrice movement, volatility, requirement change, or collateral change
Failure resultOrder may be rejected or require more equityMargin call, restriction, or liquidation can follow

What Can Change Initial Margin?

  • security type and margin eligibility
  • long position, short sale, option strategy, futures contract, or portfolio-margin treatment
  • concentration in one issuer or sector
  • market volatility and liquidity
  • broker house requirements
  • account approval level and risk controls

Common Mistakes

  • Treating initial margin as the maximum possible loss.
  • Assuming a rule minimum is the broker’s actual requirement.
  • Comparing margin requirements across products without checking whether the margin is a loan or performance collateral.
  • Ignoring open orders or unsettled trades that may reserve equity.

Official Sources

Revised on Sunday, June 21, 2026