As per my experience what i have learned in trading, it is very difficult to gain profit in the bear market, but you can still gain some profit for that you have to spend a lot of time in front of your computer, when the price of any coin comes down 10 or 15 percent buy that and when the price stabilizes you can sell it. In this way to can gain 10% profit.
It is always better to hold your cryptocurrencies when you see the bearish trend. However, if you "catch" the moment of its start, you can earn really good money. When bull run is on its peak, sell the alts.