If you leave the market, that will be a decision that I don't think is good. When this post was made in December 2018 the price of Crypto coins was indeed very low. So at that time, you have to buy lots of Crypto coins. So now you definitely feel a very high price increase. And if it is sold now it will definitely make a profit.
A lot of investors have leave the market last year, some are still here now and maybe if they will leave, they will leave with profit.
For me, I can make profit when bitcoin continues to moon, I have plenty of altcoins to sell and I need bitcoin to rise higher than the current price, hopefully a new ATH will be achieve, $20K seems to be easy now, before I thought it would be hard, but Bitcoin is just having some decent increase, hard to underestimate it and hard to ignore the possibility.