A market order buys or sells immediately at the best available price — it prioritizes certainty of execution over certainty of price. You’ll get filled right away, but not necessarily at the price you saw.

How it works

A market buy fills at the ask; a market sell fills at the bid — whatever’s available now. In a liquid, tight-spread market (like near-the-money SPY), that’s usually fine. But in a fast or thin market, the price can move in the instant your order travels, so the fill can differ from the quote (slippage).

When to use it (and not)

Use a market order when getting in or out fast matters more than the exact price — e.g., you need to exit a losing 0DTE now. Avoid it on wide-spread or illiquid options, where it can fill far from the mid. For price control, use a limit order instead; for a balance, a marketable limit.

A market order says “fill me now, whatever the price.” Great for speed on liquid strikes, dangerous on wide spreads.

The takeaway

Market orders trade price certainty for speed — fine on liquid SPY options, risky on thin ones. Know the spread before you send one. NoVo’s adaptive routing aims for good fills rather than blindly crossing the spread.