Because the daily volume of global FX markets is in excess of $4.5 trillion. The total value of all BTC in existence right now is in the low, likely single digit, billions of dollars.
A major volatility event in BTC will have an almost non-existent effect on FX markets - were every bitcoin exchanged for dollars in one day, it wouldn't even make up 1% of that day's FX trades globally.
A major volatility event in a major world currency (USD, GBP, EUR etc.) would have a massive effect on pretty much every market - it would effect FX, Futures, Fixed Income and Commodities markets, not to mention stock markets and derivatives markets.
Given the absence of the later, it's pretty safe assumption that the volatility is in BTC and not conventional FX markets.
Comments
Because the daily volume of global FX markets is in excess of $4.5 trillion. The total value of all BTC in existence right now is in the low, likely single digit, billions of dollars.
A major volatility event in BTC will have an almost non-existent effect on FX markets - were every bitcoin exchanged for dollars in one day, it wouldn't even make up 1% of that day's FX trades globally.
A major volatility event in a major world currency (USD, GBP, EUR etc.) would have a massive effect on pretty much every market - it would effect FX, Futures, Fixed Income and Commodities markets, not to mention stock markets and derivatives markets.
Given the absence of the later, it's pretty safe assumption that the volatility is in BTC and not conventional FX markets.