Why have the markets been so volatile?
Bill Ackman (Trades, Portfolio) points to the fact that a huge amount of money is traded based on nothing that has to do with long-term company fundamentals.
ETFs, leveraged ETFs, high frequency trading and so on.
Ackman tries to avoid having to worry about volatility by making sure he owns robust businesses that can thrive through all business cycles.
Here he is in a lengthy interview: