This thesis charts the evolution of US Housing financial system and housing market. The goal is to create a complex picture about wider circumstances and causes of the mortgage crisis. The first part describes the history of US mortgage market and institutions that operate on the market. The second part focuses on the securitization and entities that are in this process participating. It also explores the connections between individual participants. Thirt charter looks at the causes and entities that caused the mortgage market meltdown and examines thein motivation. The final part looks at the situation that occured after the bubble burst. Explores the trend of future regulation and mortgage market evolution