How Is a Pending Zero-Fee Transaction Similar to a Trade Order Waiting for Execution?

A pending zero-fee transaction is similar to a trade order waiting for execution in that both are subject to an uncertain and potentially delayed outcome. A zero-fee transaction is waiting for a miner's confirmation, which may never come.

A trade order, especially a limit order far from the current price, is waiting for market conditions to execute. In both cases, the user has submitted a request with a low incentive (zero fee or distant price), and the execution is not guaranteed, making the asset unavailable for immediate use or repricing.