http://www.schwab.com/public/schwab/...rs_101711.html
Key Points
Market volatility has spiked, starting with 2010's flash crash and culminating in this year's wild August, bringing asset-class correlations up with it.
High-frequency trading and the use of leveraged exchange-traded funds (ETFs) are the primary culprits, but the impact isn't all bad.
What are regulators doing and saying about the phenomenon?

Billy