Margin / Capital Requirement Estimator

Illustrate cash funding and basic US equity-option strategy-margin formulas.

How to use this tool

Long options use the full premium cash cost here. Cash-secured puts reserve the full strike obligation. A same-expiration defined-risk credit spread uses width less credit, assuming equal quantities and no uncovered legs.

Uncovered US equity-option illustrations use premium plus the greater of 20% of spot minus OTM amount, or a 10% floor (spot for calls; strike for puts). This is a simplified strategy-margin illustration, not a broker buying-power quote.

Broker house rules, portfolio margin, concentrated positions, non-US contracts, index rules, long-dated options and account permissions can differ. Margin can rise and is not a maximum loss. A naked call has unlimited upside loss even with a finite deposit.

Worked example

At spot and put strike $100 with $3 premium, one uncovered equity put gives an illustrative $2,300 requirement at multiplier 100; fully securing assignment requires $10,000 before fees.

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Model references and conventions

365 calendar days per year. Continuous rates for theoretical pricing. All examples are illustrative.