Margin Requirement Change
Risk ManagementA broker raising margin on positions you already hold, usually before an event. Free margin falls with no price move, and reduction is often forced.
A margin requirement change is a broker raising the margin needed to hold a position you already have, usually ahead of a known risk: an election, a central bank decision, a long weekend or the expiry of an index contract. Notice arrives by email and platform message, typically some days in advance, and the new rate applies to open positions rather than only to new ones.
The practical effect is a sudden fall in free margin with no price movement at all. An account comfortable at three percent margin can sit near its stop-out level at ten, and the usual outcome is a forced reduction at whatever the market happens to be offering that afternoon. Reading these notices matters as much as reading the economic calendar, because they land precisely when a position is most expensive to close.