Investing.com - Many a Wall Street firm has criticized cryptocurrencies for their volatility.Now one firm has decided to quantify that.BlackRock studied daily volatility data and concluded that cryptocurrencies are more than twice as volatile as stocks were during the height of the financial crisis in 2008-2009.Based on BlackRock's analysis, bitcoin scored a 70%. That's more than twice the 30% of the crisis period.The other two currencies in the analysis were even more volatile. Ethereum received a score of 150%, while Ripple's was 180%.Stocks' typical volatility is 10%, which is a little less than gold's. BlackRock's conclusion: Cryptocurrencies are "far from earning a place in mainstream investment portfolios."