First of all, the $500 trillion figure you mention is nowhere to be found. Most estimates have the figure at $350 billion and this is the total wealth of individual members of the Rothschild family.
Known to many as the pioneers of international banking, the Rothschild dynasty is believed to be the wealthiest family in the history of the world. According to some estimates, the Rothschild family controls assets worth more than $350 billion when each of their personal fortunes is combined.
The Rothschild empire had its genesis during the 1760s when a court Jew by the name of Mayer Amschel Rothschild founded a banking business in his native country, Germany. As a court Jew, Rothschild managed finances for the German Royals in exchange for certain social privileges such as living at court or outside of the Jewish ghettos. Over time and with the help of Mayer Rothschild's five sons, the family business expanded throughout several European countries. During 1815 and 1914, the Rothschilds controlled the world’s largest bank. Fast forward to more than two centuries, the Rothschild name is still synonymous with wealth and influence.
Source: How the Rothschild Family Created Their Wealth | Investopedia http://www.investopedia.com/arti...
Don’t forget that the Rothschild dynasty began about 250 years ago. Over time, the fortune was divided among the patriach Mayer Rothschild’s sons, grandchildren, great grandchildren, etc. Many of them are still rich, but not everyone is a billionaire.
There is still one Rothschild in Forbes’ List of Billionaires:
Benjamin de Rothschild
Net Worth As of 6/30/16
$1.52 Billion
Age: 52
Source Of Wealth: banking
Residence: Geneva, Switzerland
Citizenship: Switzerland
Marital Status: Married
Children: 3
NOTE: There is a Jeff Rothschild, a Facebook adviser who is worth $2 billion, but he is NOT related to the Rothschild banking family.
EDIT July 14, 2016
I have become quite fascinated by the history of the Rothschild family and my view has changed somewhat after reading all sorts of articles on the Rothschild clan.
I think dilution of the wealth to descendants is only one part of the answer. The other is the fact that they have been extremely secretive about their wealth.
There are reports of various branches of the Rothschild families buying a private bank in France, buying vineyards and lots of land in New Zealand and Chile for vineyards, but the net worth of the various branches of the family is never mentioned.
Even the worth or percentage of the stakeholdings of the Rothschild members in investment companies, financial firms and banks bearing their family name are not mentioned, even in the companies’ websites.
There are also reports that the Rothschild family controls the major news agencies, newspapers and even TV networks in the US. The reports claim that the top editors of these agencies and networks have been told never to mention the Rothschild name in their reports. I have yet to confirm these reports (which shows how secretive they are).