Margin requirements are the amount of cash or buying power your brokerage account must have available to hold an options position.
To sell a put option, your broker holds cash equal to the cost of assignment. You don't lose it unless assigned, but you can't use it for other trades.
Example: Sell a $150 put. Broker requires $15,000 available (100 × $150).
Buying options: No margin required. You pay the full premium upfront.
Selling options: Margin required. Broker reserves cash/buying power.
Your total buying power = Account value - amount already used for margin.
If your account is $50,000 and you use $15,000 for a put, you have $35,000 buying power remaining.
Different brokers have different requirements. Check yours.
Higher levels allow riskier strategies but require experience.
Related: Maintenance Margin, Portfolio Margin, Buying Power, Cash-Secured Put
