Everything can. nothing has to! Do not forgett, cryptocurrencies are high risk investment. So it could be happen any time that it go down to zero. When bitcoin would loose his value, all other cryptocurrencies would go down with it. But it can happen also the opposite like end of last year. Bitcoin started a bullrun and rised the price of every altcoin with him to the moon. SO nobody can know what happends in the future. So just be patience and hold!