Depending on what kind of altcoins you are holding the strategy that you need to adopt will have to change, if you are holding good altcoins as you claim then you really do not have any reason to sell them now as if you are willing to hold for the long term not only you will recover your money but you will even make profits, however for someone holding bad altcoins then it is critical that they sell as soon as possible as even if they will lose money by selling now they will lose even more money if they keep holding.