I'm quoting below from a Wikipedia article
The forex market is a cash inter-bank or inter-dealer market, which was established in 1971  when floating exchange rates began to appear. The foreign exchange market is huge in comparison to other markets. For example, the average dailyvolume of US Treasury Bonds is $300 billion and the US stock market has an average daily volume of less than $10 billion. Ten years ago the Wall Street Journal estimated the daily trading volume in the forex market to be in excess of $1 trillion. Today that figure has grown to exceed $1.8 trillion a day.
Correct me if I'm wrong, but I think that means:
Equities: $10 billion
Fixed Income: $300 billion
Forex: 1.8 Trillion
Traded on a daily basis.
What do these numbers really mean though? Does it mean that there is the potential to generate more money from Forex, and Equities trading?
Does it mean that Forex is "the biggest game out there"?
Do banks have prop desks for Forex Trading?
I'm just trying to understand these things, I'm still learning.