Orders & execution
Market order
An instruction to trade immediately at the best price currently available, whatever that is.
How it works
A market order prioritises certainty of execution over certainty of price. It will almost always fill, and it makes no promise about where.
In a large, liquid share during normal hours the difference from the quoted price is usually trivial. In anything thin, fast-moving, or outside regular hours, it can be substantial.
Where it misleads people
A market order on an illiquid security can walk through several levels of the book and fill far from the last quoted price. This is the single most common way a beginner loses money on the mechanics rather than the idea.
Related terms
- Limit orderAn instruction to trade only at a specified price or better, accepting that it may never fill.
- SlippageThe difference between the price you expected and the price you actually got.
- Order bookThe live list of every outstanding buy and sell order, arranged by price.
- Flash crashA very sudden, very deep price fall that reverses almost as quickly.
Mentioned in
More in Orders & execution
- Market timing
- Good-till-cancelled
- Stop-limit order
- Fractional shares
- Time in the market
- Fill-or-kill
- Trailing stop
- Dollar-cost averaging
All 12 Orders & execution terms · The full glossary, 433 terms
Educational reference only. Nothing here is investment advice or a recommendation to buy or sell anything, and tax treatment depends on your own circumstances and the country you are in.