It depends on what the cryptocurrency is. If you bought a fringe pump and dump currency that has no real technology, no people or companies actually using it and there seems to be no news or development ongoing then you probably should consider just taking the loss and learn from it. If you are holding any major coins that have active partnerships, real technology to offer, and are actively being developed and adopted such as Cardano, Ripple, Ethereum or Bitcoin then you need to hold because we are still very early in blockchain technology and these market lows have happened before and is a normal part of a market cycle. Long term is the play on those. Remember it took Amazon almost two decades to get where it is today.