Hold during a bull market. If you sell, you might lose your position where you may never regain again. Like Bitcoin at $1000 in the beginning of 2017. Now, in a bear market if your able to sell early, you may be able to let the market correct far enough so you can pick a new position at a much cheaper price. If you try to sell too late at near bottom prices, then you might also lose your opportunity so it's better to Hodl. It all comes with experience so practice now.
First of all, HOLD is the most simple and easy way and yet the most effective way at the same time. Why ? That is because holding does not need a lot of effort and I think everyone can do that. Besides, in the other hand, HOLDing is very good and the most suitable thing for newbie or beginners to this world of crypto. Trading really needs a lot of effort because we need to monitor the price all the time and we can have so much risk on that. You can lose and win for like anytime, unlike holding. That is because holding only need the final result and the true holder will not sell no matter what until they get profit.
The holder is easy to become a gambler if you place blind faith in a wrong decision. I was a holder, I lost a lot of money when I put my trust in DGB when I bought it at 2000 satoshi for each. Ok, do not talk about the past. Just in the past four months, the price of ETH has changed unexpectedly, from the highest price of $ 1400, it fell to the $ 300 price again. If you do not put too much faith in the market, you can continue to buy ETH with 4 times cheaper in a short time.