Margin

Initial and variation

Initial margin is required to open. Variation margin settles the day’s gain or loss. On futures this happens through the clearing system. On a securities margin loan, a maintenance requirement plays a similar role. House requirements set by the broker can be higher than the regulatory minimum and can be raised when volatility rises, which is exactly when cash is hardest to find.

The call

A margin call is a demand for cash or for a smaller position. Firms do not have to wait for you to answer the phone. The agreement usually lets them liquidate. In fast markets they may liquidate at poor prices and you may still owe a shortfall, depending on the product and the local negative-balance rule. Know which rule applies before you need it.

Pattern day trading, briefly

US margin accounts can fall under pattern-day-trader rules if a client day-trades frequently. Equity minimums and the definition should be read from current FINRA and broker materials. The rule is a constraint, not a badge. It does not apply, in that form, to every country or to every cash account.