depending on the broker u use , you can put in a stop loss. you can hold the coins for as long as you want to. ive been holding on to a small amount of wanchain for 3 years. i bought them at a high price and since then its been steadily losing value. in this bull market its starting to make a comeback. do your own due diligence. dont just jump into anything like i did!
lots of opportunity in this market atm.
cryptos dont force you to get out. you own the coins, digitally of course. you can keep them on the exchange or you can put them in a wallet.