What is the meaning of Front_running?

The illegal practice of a stockbroker who, on receiving a large client order, places an order for his or her own account ahead of the client's, knowing that when the client's order is placed it will move the market and create a profit for the broker.

The illegal practice of placing orders for a security on one's own account in advance of promoting or recommending it.

Any practice of buying something the value of which is about to increase due to a future purchase by another, especially where the knowledge derives from a fiduciary relationship.

present participle and gerund of front run

Source: wiktionary.org