Wolong did that to Dogecoin and other alts. He made a fortune pumping the price and dumping on his co-conspirators. He never tried the same stunt with Bitcoin because it costs too much money to manipulate Bitcoin's price. Five million dollars spread across all the exchanges that matter isn't enough tp pump Bitcoin.
i think the proposal in the OP and wolong was not based on 5 exchanges..
the intention was not to cause a permanent rise..
its just a pump&dump on one exchange so the organizer (guy in charge of shouting when to buy and sell) can profit.
on a BTC market, the spread is crap and not alot of middle men would profit. only on altcoins would the price increase significantly enough for a certain % of middle men to also profit along with the organizer.
BUT...
it would also require it to be a popular and high volume altcoin where the pump and dump group were not just circle jerking themselves but also trading against lots of people not in the group. otherwise them middlemen wont profit if its a pure panic pump&dump and the only players are the group.
i do not recommend it at all. not now.. especially on the bitcoin-dollar market.