lol.
a pump by nature is a fake higher price which is happening every day among altcoins. and you don't have to do anything at all for it to come down, it will do it on it s own because it is a fake price. it is like blowing into a balloon, it won't expand forever. it will pop at some point.
I suspect they are using them Powerful Quantum Computers to do the hash calculation
that is just your lack of understanding about how hashes work and what a QC is!
They have access to any volume amount of any coin that they want
this is a concern with all the PoS shitcoins that you can control that shitcoin by owning a lot of it.
it is not applicable to bitcoin.
I have seen it happening over and over again
"they" in this context are the regular pump and dumpers who use the newbies to pump their shitcoin and dump it on them after they get their own profit.
if you don't want to lose money then stop trying to "invest" in shitcoins.