And this is the whole thing. Bear market allows you not only to see where your investments are going but also lets you easily unwind them by selling poorly performing coins (if we talk about cryptos) and then proceed to buy more resilient coins at half the price as the market goes downhill. That's what most people overlook in bear markets and so fail to take advantage of. In a nutshell, it is a perfect time to change sails or even the ship itself, tide or no tide
This would be "buy high, sell low".
Concerning traditional investments, a smart asset allocation would tell you to do the opposite.
However, as we are in this crazy cryptocurrency market, I don't think it would be wise to buy more of a coin that lost 90% of its value (as it may never recover)
I have a few coins that lost about 90% of their value... they are almost worthless now. I will not sell them... because they aren´t worth anymore.. but I will hold, and see if they recover at least a little so I can sell in the future...