BitCoin's market cap in USD is currently $282.7 Billion. There are only 3 currencies that rank higher in terms of total circulation.
United States (USD)- $1.51 Trillion
Euro - $1.22 Trillion
Japan (Yen) - $915 Billion
Next on the list is India's rupee at $196 Billion followed by Russia's ruble at $145.1 Billion. It's astonishing that a cryptocurrency ranks so high compared to major currencies around the world.
Even more astonishing, BitCoin isn't the only cryptocurrency that stacks up so well against worldwide currencies. Ripple's market cap is now $115 Billion followed by Ethereum at $96 Billion.
Sources:
https://en.wikipedia.org/wiki/Circulation_(currency)
https://coinmarketcap.com/