Every time someone says "X people have a higher net worth than Y% of people COMBINED" I get very, very skeptical. Some net worths are negative. Some net worths are significantly negative. A homeless man has a much higher net worth than 8,000 people who just graduated from medical school with some debt combined. Relevant article.[1]

[1] http://blogs.reuters.com/felix-salmon/2014/04/04/stop-adding...