it could happen because every trade there must be a black game that will always exist from time to time but the system they do that is not in the know by the crowd.
I think it's impossible because I know the market price is not possible to manipulate but the possibility for altcoin prices can be manipulated, and the possibility of altcoin and bitcoin prices now declining is probably due to manipulation whereas crypto market also cannot be returned to the original price than from now on it is better we hold our altcoin and wait for all the good back
I also would like to believe that it is impossible to manipulate market prices, but how can we then explain the insane price growth in December last year?