A limit order can execute immediately if its price crosses the book.
Market orders prioritize immediacy
A market-style order attempts to trade against available liquidity. The displayed quote is only a reference: different parts of the order can fill at different prices. A slippage constraint can prevent some or all execution if prices move too far.
For a larger order, look beyond the best bid or ask. A small quantity at the top of the book may not support the entire trade at that price.
Limit orders define a boundary
A buy limit sets the maximum acceptable price; a sell limit sets the minimum. The order may wait, partially fill, or execute immediately if it can match existing liquidity at that price or better.
A sell limit well below the market does not reserve a cheap short entry. It is marketable and can fill near the current bids, so its required margin can be much larger than quantity multiplied by the low limit.
Inspect time in force
Good till cancelled allows a remainder to rest. Immediate or cancel removes any unfilled remainder. Post only is intended to add liquidity rather than execute immediately; a crossing request may be cancelled.
Whichever type you choose, inspect the execution result. An accepted order is not the same as a full fill, and cancelling an unfilled portion does not reverse completed fills.
A marketable sell
If bids are near $100, a sell limit at $90 can execute near $100. For 10 units, the exposure is around $1,000, not the $900 implied by using the limit alone.
Illustrative figures only. Not a price forecast or trade recommendation.Further reading
Protocol details and market rules can change. Check the current specification before trading.
Educational content, not investment advice. Trading perpetuals can result in substantial loss. Market access is subject to eligibility and location. Product disclosures.