Long Positions (Buying)
When you buy a call or put you pay the premium up front, and your risk is capped at that premium. There is no maintenance margin and no liquidation for a long position — the amount reserved to open it covers the premium plus a small buffer for fees, insurance, and slippage.Short Positions (Selling)
Selling an option collects the premium but takes on open-ended risk, so it requires an initial margin (IM) to open and a maintenance margin (MM) to keep open. Both are sized from the contract’s index and mark prices (roughly 15% of index for IM and 5% for MM, with mark-price floors and an out-of-the-money discount — a reduction for contracts whose strike is far from the current price) — see Margin & Fees for the precise formulas.Liquidation
Positions are monitored continuously against maintenance margin. Liquidation is triggered at the account level: when your maintenance margin reaches 98% of your total equity (maintenanceMarginRatio above 0.98, where equity is your balance plus unrealized PnL),
the system reduces or closes at-risk short positions to bring the account back within limits.
Only accounts holding short positions or open sell orders are margin-monitored. Because a
long position can’t lose more than the premium already paid, it is never liquidated and
carries no liquidation price.
Checking Margin and Account State
- Per-position margin is published as
initialMarginon the Positions Stream. - Account-wide collateral, margin in use, and PnL are on the
Account Summary. Watch
maintenanceMarginRatioto gauge how close the account is to liquidation. - To size an order, Get Margin returns the per-unit cost and the maximum quantity your balance can afford, and Get Contract Pricing returns the margin and fees for a specific order.