Market orders are not available until the market has its first trade

A market order is protected by a price range around the last trade price. On a new market there have been no trades yet, so there is no reference price, and market orders are not accepted. Place a Limit order instead. After the first trade on the market, market orders work as usual.

Only part of the market order was filled

A market order is filled only at prices within a limited range around the last trade price. If the order book does not have enough orders inside this range, the rest of your order is cancelled and the funds for it stay on your balance. This protects you from buying or selling at a much worse price than expected. Use a limit order if you need a specific amount at a specific price.

Market price is unavailable

For a market buy by total, the form needs a current price to check your balance. Wait until the order book loads or use a limit order.

Other messages

Insufficient balance: there are not enough available funds on your Spot wallet. Funds reserved by other orders are not available. Move funds from Funding: How do I move funds between my accounts?
Min. amount or Min. total: the order is smaller than the market minimum shown in the message.
Trading on this market is temporarily paused: trading on this pair alone is paused, other pairs trade. A market order that was still waiting on this pair is cancelled and its funds return to your balance: Trading is temporarily halted
Trading on this market has not started yet. Please wait for the opening time.: the pair is new and opens at the time shown on its trade page. Trading on this market has ended. The pair has been delisted.: the pair is no longer traded, and your open orders on it were cancelled with the funds returned: When does a new pair open, and what happens when a pair is delisted?
This market is not available: this pair is no longer traded.
This order would trade with your own order. Cancel that order or change the price.: the first order in the book your order would trade with is your own (or one of your sub-accounts'), so it is not placed. If the rest of an order was cancelled for this reason after a partial fill, the site says "The rest of your order was cancelled: it would have traded with your own order.": Why was my order cancelled when it met my own order?
Trading is temporarily halted: trading is paused on all markets. A market order that was still waiting when the pause started is cancelled and its funds return to your balance: Trading is temporarily halted

Why was my market order rejected or not fully filled?