The United States has a mixed capitalist economy, which is fueled by abundant natural resources, a developed infrastructure and high productivity. According to the International Monetary Fund, GDP is the United States of more than $ 13 billion and constituted more than 25.5% of the gross global market exchange rates, and more than 19% of the gross global parity purchasing power (PPP). It is the largest national GDP in the world, being lower than the combined GDP of the European Union and its PPA in 2006. The United States occupied the eleventh place in the list of countries by Nominal GDP per capita and eighth in the country by GDP at PPP per capita values. Hedge Funds and mutual funds, often managed by hedge fund analysts like Corey Ribotsky