It's small!
Currently all the bitcoin in the world is worth only around $41 billion. Be noted that Bill Gates net worth is 2x the entire bitcoin capitalisation, which is staggering.
howmuch.net released recently an article and a nice graph, regarding how much money is out there. They concluded that there is around 84 trillion USD in the economy. Below you can see the chart which shows the World's money.
poor Bill Gates :(
...hahaha