Many hedge fund managers have become billionaires; perhaps this - plus their reputations as the smartest guys in the room - is why they have captured the investing public's imagination.

Hedge fund managers charge so much more than mutual fund managers; alpha is even harder to come by. They end up selling a variety of things beyond mere outperformance.

Mutual fund managers want your money in their funds. They get paid based on assets under management.

Hedge funds are not especially liquid. Many are 'gated' - meaning there are only small windows when you can withdraw your money. They typically have a high minimum investment and often require investors keep their money in the fund for at least one year.

If your investing approach requires that you become Nostradamus to succeed, then you are destined to fail.

The ability to select stocks, manage them over time and know when to sell them is incredibly difficult, even for professional fund managers.