It depends on the market, some equity markets have relatively strict market manipulation regulations that prohibit this kind of activity (in the same way you ca

It depends on the market, some equity markets have relatively strict market manipulation regulations that prohibit this kind of activity (in the same way you can't spread a rumour for the purpose of manipulating a share price). One of the reasons banks have compliance departments is so that can check the legality of particular types of behaviour before they employ new trading strategies as there can be a very thin line between what's legal and what's not.