A country's trade balance reflects the difference between exports and imports of goods and services. The trade balance is one of the biggest components of the Balance of Payment, giving valuable insight into pressures on country's currency.
Surpluses and Deficits
A positive Trade Balance (surplus) indicates that exports are greater than imports. When imports exceed exports, the country experiences a trade deficit. Because foreign goods are usually purchased using foreign currency, trade deficits usually reflect currency leaking out of the country. Such currency outflows may lead to a natural depreciation unless countered by comparable capital inflows (inflows in the form of investments, FDI - where foreigners investing in local equity, bond or real estates markets). At a bare minimum, deficits fundamentally weigh down the value of the currency.
Ramifications of Trade Balance on Markets
There are a number of factors that work to diminish the market impact of Trade Balance upon immediate release. The report is not very timely, coming some time after the reporting period. Developments in many of the figure's components are also typically anticipated well beforehand. Lastly, since the report reflects data for a specific reporting month or quarter, any significant changes in the Trade Balance should plausibly have already been felt during that period - and not during the release of data.
However, because of the overall significance of Trade Balance data in forecasting trends in the Forex Market, the release has historically been one of the most important reports out of the any country.