open market
noun [ S ]
ECONOMICS ukusan economic system where there are no rules about how much of something people can buy and sell:
The EU is meant to be an open market, with no restrictions on purchases and sales within its borders.
FINANCE
a situation in which a country's central bank buys and sells in a financial market to increase or reduce the money supply (= the amount of money in an economy):
When a central bank conducts open market operations, conditions in the financial sector could be affected.