Why does a limit order remain pending?

A limit order stays pending simply because the market hasn’t reached your set price with enough matching quantity to fill it. If you placed a buy limit below the current market price, or a sell limit above it, the order will sit there until the stock trades down (or up) to that level, which might happen quickly, slowly, or not at all during the order’s validity. Low liquidity in the stock, a price gap on the opening bell that skips right past your limit, or setting a price too far from the current market are the most common reasons a limit order lingers unfilled. You check the current market price against your limit price and the order’s validity (day order versus a longer duration) when you want to understand why a specific order hasn’t executed.