Several ponzies around without such effect.
They should cause a dump, not a pump
First they make a pump and after they make dump. It's even rime. Problem is that fall is bigger then rise. This ponzi schemes and other 100% and more return investment are around us for some time, I just don't get it how people still believe in that? It's obviously a scam and people still put their money into this things, doesn't matter if its fiat or altcoins. When will they finally be a bit smarter.
If the fall were bigger than the rise, we wouldn't still be up over 3 Million Percent since Bitcoin's inception only 6 years ago