Day order
A day order is an instruction to buy or sell a security that automatically expires at the end of the trading day if it has not been filled. If the price never reaches the level needed to execute the order, or if there simply is not enough matching interest, the order is canceled when the market closes and does not carry over into the next trading session. This is the default order duration on most brokerage platforms unless an investor specifies otherwise.
The alternative to a day order is typically a , which stays active across multiple trading days until it either fills or is manually canceled. Choosing between the two comes down to how the investor wants stale orders handled. A day order forces a fresh decision every session, since any unfilled limit or simply disappears overnight and has to be resubmitted if the investor still wants it in place. A avoids that resubmission but carries the risk of an old, forgotten order suddenly filling days or weeks later if the price happens to move back to that level.
Day orders are useful when an investor's view on a is tied to that specific session, for example an order meant to capture an anticipated move around a particular day's news or . Since the order does not persist, there is no risk of it executing unexpectedly on some later day when the circumstances that motivated it no longer apply.