it was not -10% then +10% or vice versa at all.
and day trading is certainly not safe in a market where price is falling. it is highly risky, riskier than it normally can be.
the only case where it can be a good idea to invest in such a market is if you see a very huge dip and are nearly sure that price will bounce back so you buy in that dip. but also the profit in cases like this are too small to be worth it. meanwhile in other altcoins price are rising with a much smaller risk and a much bigger profit!
so why you would choose a high risk low reward over a low risk high reward is beyond my understanding!