Just wait for a few day before you sell you alt. The best move right now is to monitor the price gap depreciation before you decide to sell your alt. If you see the value of your alt is continuously decreasing i think it's time to decide but think of it before you do sell and calculate first if your profit and investment not loss. If you think you continuously losing your profit and capital i think its time you to decide if have no chance to increase the value of your alt. But if you feel that have a chance to increase again the value of your alt, why you don't try to hold your alt to gain profit simultaneously.
For now it is better to hold your altcoins and Bitcoins. Look at the graphs: almost all cryptos started to grow and come to green zone. I might suppose even that the panic was done artificially to let big dealers to buy cryptocurrency for cheap. Do not sell your alts. IMHO.