Federal National Mortgage Association, operating as Fannie Mae, was chartered by the US Congress to provide liquidity in the secondary mortgage market, increasing the availability and affordability of homeownership for low, moderate and middle-income families. However, the business is self-sustaining, being funded exclusively with private capital and receives no financial guarantees from the US government. The company is now the largest home funding source in the United States and the largest non-bank financial services company in the world.