A market order only partially fills when there aren't enough orders on the opposite side of the order book, or when your account balance is tied up in other unfilled orders. A market order is designed to immediately consume available resting orders. If your order size exceeds the total depth at the best bid/ask, the system will automatically go down to the second level, third level, and so on until your order is completely filled. If it can't be filled fully, it means the order book depth has been exhausted.
Step 1: Check if there's enough depth using the order book
Before blaming the system, go to the trading page and look at the order book. A market buy order will consume all sell orders at the ask level (and beyond). If you want to buy 10 BTC but the total sell orders across the first ten levels only sum to 2 BTC, your order will only fill 2 BTC, and the remaining 8 BTC will either partially fill or expire.
How to do it: Open the depth chart for your trading pair and check the total volume near the top bid/ask levels. If your order size is much larger than the combined volume of the nearest levels, a partial fill is normal—not a system glitch.
Completion criteria: You can see the gap between your order amount and the available depth on the order book.
Common failure: Placing a market order on a new or low-liquidity trading pair often results in partial fills. For example, on Christmas Eve 2025, a large market sell order on Binance's BTC/USD1 pair—which had very thin liquidity—caused the price to plunge from $87,000 to $24,000, while the main BTC/USDT pair was completely unaffected. This is a classic case of price distortion caused by insufficient depth.
Step 2: Check if your funds are locked by pending orders
Sometimes the issue isn't market depth—it's that your money is tied up in other open orders. For instance, if you placed a limit order that hasn't filled yet, that portion of your balance is locked by the system. When you then submit a market order, the system sees insufficient available balance and either rejects the order or only fills part of it.
How to do it: Go to your "Open Orders" or "Unfilled Orders" list and check for any unfilled limit orders, stop orders, etc. If there are any, either wait for them to fill or cancel them manually to free up your balance before placing the market order.
Completion criteria: Confirm that your available balance fully covers the amount you intend to trade.
Step 3: Know the difference between "partially filled" and "immediately expired"
Different order types handle partial fills differently. Binance's spot market order fills as much as possible and cancels the rest. For futures market orders, there are price protection mechanisms with upper/lower limits; if the current price deviates too far from the mark price, the market order may expire immediately or stop after a partial fill.
How to do it: Check the "Status" field in your order history. "Filled" means the entire order was executed. "Expired" means it was partially filled and the remainder was canceled by the system. "Canceled" means you manually canceled the order.
Completion criteria: You can clearly identify how much of your order filled and whether the unfilled portion expired or was canceled.
High risk: Placing a large market order in a low‑liquidity market can cause severe slippage—the system eats through far‑away price levels to fill your order, making your average fill price much worse than what you saw when you placed the order. Market orders are best for small amounts or highly liquid major pairs. For large orders, using a limit order is safer and more predictable.
