Liquid assets held by a country's government or central bank for the purpose of intervening in the foreign exchange market. These include gold or convertible foreign currencies, for example US dollars for countries other than the United States, or DM for countries other than Germany, and government securities denominated in these currencies. Foreign exchange reserves can also include balances with international institutions, notably the International Monetary Fund (IMF). They do not include working balances of foreign currencies or short-dated foreign securities held by a country's banks or other firms, but in an emergency some of these could probably be added to a country's foreign exchange reserves.

• short-dated security
• short position
• short run
• short-run capital movements
• short-run cost curve
• short-run marginal cost
• short-run Phillips curve
• short-termism
• short-time working
• shut-down price
• SIB
• SIC
• sickness benefit
• side-effects
• side-payment
• sigma
• signalling
• significance, tests of
• silicon valley
• simple interest
• simulation
• simultaneous equations
• sine
• single currency
• Single European Act, 1986