In my high school American History text, it told of how the Great Depression was preceded by speculation in the stock market. Speculation on stock led to the historic stock market crash in 1929 that brought on the Great Depression. It was fueled by "buying on margin" / with few regulations on stock market purchases, in the months and years leading up to the Great Depression, investors were able to buy stocks on margin, with the only requirement that they put 10% down. In other words, they could buy $100 worth of stock for a $10 investment, and if that stock went up by a mere 10%, they’d doubled their investment. This "leveraging" led to wild speculation, with people cashing in their life savings to funnel it into the stock market, which led to artificially high prices. Stock market regulations were put in place during the Great Depression to prevent the same catastrophe from repeating in the financial markets, but seventy years later, Americans
aimed a similar greed toward the housing market. Millions of people bought homes they couldn’t afford, with money they didn’t have, taking out 100% or 110% loans. Speculation on housing prices in 2003-2007 brought on the current recession.
http://www.museum.siu.edu/museum_classroom_grant/Museum_Explorers/school_pages/bourbonnais/page1.htm
http://www.thegreatdepressioncauses.com/then-and-now.html