Central banks do participate in the Forex market by intervening in it. The goal of central banks, however, is not to make a profit. The goal is to influence the market to satisfy their monetary policies. These goals typically include maintaining stable prices and stimulating or curtailing economic growth. Central banks also manipulate the market by setting the interest rate, purchasing government securities and other means. The eventual result of all this manipulation is to increase or lower the value of the country’s currency in relation to another currency.