How big is the Trading Volume in Retail FX?

And how it affects investors trading experience

The Retail FX trading reported by the Bank for International Settlements is in the vicinity of $185 billion, just about 3.5% of the $5.3 Trillion of the global interbank market. But here is the most important detail to this figure. Of the $185 billion, $78 billion was registered as FX spot trading and with this figure comes with $74 billion are in "Forex Swaps". (Figures based on BIS)

How big is the Trading Volume in Retail FX?