A Market order asks to buy or sell at the best prices currently available on a specified market, without setting your own fixed limit price. The exchange matches it against waiting offers under its rules. Prompt execution takes priority; the displayed price, full completion and total cost are not unconditionally guaranteed.
Hana wants to buy bitcoin for dollars on her chosen exchange. Her market buy matches sellers’ offers, starting at the best ask, the lowest offered selling price. A market sale would instead take the bid, the highest buyer’s offer. These waiting orders form the order book. Execution does not automatically occur at the midpoint or the last trade price. Seeing a number next to Bitcoin is therefore not enough: Hana needs to know the actual market and currency she is trading. [1] [2]
In our example, Hana requests 1 BTC. Only 0.25 BTC is available at the best price of 60,000 USD. She buys the remaining 0.75 BTC at 60,040 USD per bitcoin. Adding the actual purchases gives a total of 60,030 USD before fees. Because she bought a whole bitcoin, this is also the average price per bitcoin. For a smaller or larger quantity, divide the total value by the bitcoins bought. The best offer was not a promise for the entire order; available quantities mattered too. These are illustrative figures, not live quotes. [1] [3]
Hana saw an offer when she made her decision. Before her order reaches execution, someone else may take it or the seller may cancel it. The last displayed price does not reserve bitcoin for her account. The difference between an expected and actual price is called Slippage. That difference alone does not establish an exchange error; the sequence matters. Submission, acceptance and individual execution times help explain it. Comparing yesterday’s average with today’s purchase answers a different question from checking her own order. [1] [2]
Hana might think “I want to spend 600 USD” or “I want a certain quantity of bitcoin.” At 60,000 USD per BTC, the first amount corresponds to 0.01 BTC before fees. An order for 0.01 BTC does not fix the dollar expenditure if the price changes. Conversely, a fixed cash budget does not predetermine the exact bitcoin quantity. Interfaces have different fields and rules: check what is being entered and whether the amount includes fees or requires extra funds for them. An order estimate is not the final statement. [1]
A market order uses offers already waiting. Coinbase therefore classifies it as Taker in its rules: it removes available liquidity, the opportunity to trade with ready counterparties. That does not make the service free. Apply a purely assumed rate of 0.1% to our purchase value of 60,030 USD. The fee would be 60.03 USD and the total expenditure 60,090.03 USD. This is not Coinbase’s current fee schedule or an exchange recommendation. The actual account and market fee rate and how the fee is charged determine the real cost. [1]
Prompt processing is no promise to finish at any price. Coinbase, for example, uses a Price Protection Point, a price boundary beyond which matching stops. The available portion may fill and the system may cancel the rest. In a separate model, only 0.25 BTC of a requested 1 BTC is bought, while the remaining 0.75 BTC is canceled. This does not mean the whole bitcoin was bought, nor does the canceled part wait as a limit order. Each market defines its protections; do not infer them from another exchange or our illustrative quantities. [1]
Hana may also encounter a Stop order, which activates when a specified price is reached. That alone does not tell her what activation submits. Investor.gov’s general stock-market description says a stop becomes a Market order. By contrast, Coinbase Exchange rules for the stop orders described there require Stop Limit, a limit order triggered by a price condition. These procedures are not interchangeable. A trigger price is not automatically an execution price, and a limit also affects the risk that the trade will not finish. [1] [2]
After submission, Hana checks the BTC actually bought, average price, fee and status of the unfilled portion. “Order accepted” is not proof of a trade; acceptance and completion are different stages. A credit on an exchange account is also not a withdrawal to her own wallet. Withdrawal is a separate step, and a transfer over Bitcoin needs its own confirmation. Buying, account records and taking bitcoin into self-custody are connected but distinct events. Keeping them separate helps with routine checks and investigating problems. [1]
For the clearest picture, read this entry together with Slippage, Limit order, Order book, Bid–ask spread. The reverse links also lead from Market maker, Bid–ask spread, Slippage, Limit order.