Market manipulation is the attempt to artificially increase or decrease the price of a security. It is artificial because the manipulator is attempting to skew supply and demand to push the price in a favourable direction for them.
While supply and demand for an asset can change at any time based on other fundamental analysis factors, including news announcements, earnings reports and investors’ decision processes, manipulation typically involves illegal means, such as spreading false information, trying to influence price quotes or posting fake orders.
While market manipulation is usually thought of in terms of assets such as stocks, currencies, or commodities, manipulation can also affect other things such as overnight interest rates, resulting in millions of dollars being made or lost. Such manipulation may require the central banks or other regulatory bodies to intervene.