Well only newbies or investors who dont understand how crypto works will ask these questions. But those who already here for long period are used to this kind of situation. The maket is volatile and its quite normal seeing the price of coins fluctuating, if the coin you hold happened to turn zero then its likely a shitcoin who dont have real use cases.

So buy a coin that is worthy to include in your portfolio and as usual hold until the price skyrocket.