It's hard not to sound a bit conspiracy theorist when talking about them, but no one knows their wealth. They own along with some others, the US federal reserve. They basically earn interest on every dollar borrowed in the USA, and in many other countries including the UK. Their reach is unknown but they are commonly referred to being the leading family in the shadow global government.
They along with others "own" the U.S. Federal Reserve? What's your source for this claim?
I think Wiki sums it up best:
"Many conspiracy theories about the Rothschild family have been identified as a result of anti-Semitic prejudice reaching back several hundred years, including the era of the Napoleonic wars, and not as a result of valid evidence."