bagholder

A bagholder is someone left holding a worthless or severely depreciated investment after others have sold.

The term evokes someone stuck with the bag after everyone else has fled.

Common in cryptocurrency and stock trading communities, it often implies the person bought into hype too late or held too long: I'm a bagholder now—bought at the peak and it crashed 90%.

Sometimes used self-deprecatingly by investors who refuse to sell at a loss.