COMMERCIAL COMPANIES- these commercial companies trade small quantities of foreign currencies compared to larger banks and their trades produce small and short-term impact on the market rates. However, the trade flows from transactions made by commercial companies are essential factors with regards to the long-term direction of the exchange rate of a certain currency.
CENTRAL BANKS- central banks play an important function in the Forex market. They have the control over the supply of different currency, inflation, and interest rate. In addition, they have also official target rates for the currencies that they are handling. They are responsible for stabilizing the Forex market through the use of foreign exchange reserves. Their intervention in the market is enough to stabilize a certain currency.