What the Indicator Shows
GDP is a representative indicator of the size and growth of an economy. There are two versions: "nominal GDP," which includes the effect of price changes, and "real GDP," which excludes it. It is commonly discussed in terms of the growth rate — the rate of change from the same period a year earlier or from the previous quarter. In Japan, the Cabinet Office publishes preliminary and revised figures every quarter.
Relationship to the Markets
The GDP growth rate is a factual tally of overall economic activity in a country, and financial markets can react to the published results, but the GDP figure itself does not determine future stock price movement. It is useful to keep it in view as one of many indicators of the economy, alongside other statistics.