https://news.bitcoin.com/fx-market-shrinks-bitcoin-expands/
According to the BIS
Global FX turnover fell to $5.1 trillion per day in April 2016, from $5.4 trillion in April 2013
The scale of global FX turnover indicates that Bitcoin is microscopic compared to FX trades. The volume of Bitcoin traded at global exchanges is ~ $60-70 Mn (excluding inflated Chinese trade volumes). So we have to increase by around 100,000 times before we get close to FX trades. Given how small Bitcoin currently is, it would be ridiculous to link Bitcoin and the drop in global FX trade.