As of 2014, global GDP was $77 trillion. The total market capitalization of all world stock markets is approximately $70 trillion, and about a fourth of that amount is the U.S. market.
The U.S. economy is the largest by GDP, which for 'fiscal year' (FY) 2016 was approximately $19 trillion. The total value of notional derivatives fell to $18.1 trillion.
How Many Dollars do We Have in Circulation?
What is Currency in Circulation?