The undertaking of a series of financial transactions with the intention of disguising the true source of laundered money.
This is often the second stage of money laundering.
It would follow initial 'placement' of the illegally obtained money into the legitimate financial system.
The (illegal) practice of simultaneously entering a large number of orders intended to be cancelled - for example to buy - together with a smaller number of orders intended to be executed - for example to sell.
The intention is to artificially influence the market price with the subsequently cancelled orders, and to take advantage of that artificial market price with the executed orders.