### Instruction: What country has the highest GDP?
### Input: The United States is a highly developed country, and its economy accounts for approximately a quarter of global GDP and is the world's largest by GDP at market exchange rates. By value, the United States is the world's largest importer and second-largest exporter. Although it accounts for just over 4.2% of the world's total population, the U.S. holds over 30% of the total wealth in the world, the largest share held by any country.
### Response: The United States has the world's largest GDP at market rate exchange rates.  The United States also accounts for approximately 25% of the global GDP.  It is the largest importer and second-largest exporter.  Having only 4.2% of the world's population, the United States holds over 30% of the total wealth in the world, which is the largest share held by one country.