In this thesis, we examined time period from year 1993 to 2008 concerning real estate market in USA and coherent risk management decisions and tools used by US government and private mortgage institutions. After qualitative analysis of information resources (financial data, official documents and statements, economic researches and comments), we tested hypothesis of underestimation of real estate price bubble in years 2000 to 2007 by mortgage agencies and US stock market. The tool we used was linear regression (ordinary least squares method) to examine pricing of mortgage-backed securities by mortgage agencies and pricing of mortgage bank Fannie Mae stocks by investors.