Is buying altcoins intended to be held for a long time? I don't like long-term investment in (unknown, unpopular) altcoins. I'm afraid that if I open my wallet one day, all the money in it will return to zero.

When I invest in altcoins, I will always observe the price of the coin. If the price is not optimistic, I may stop the loss in time. I will hold Ethereum for a long time, I think it is the center of the altcoin.