... Any pension fund manager who doesn't have the vast majority-and I mean 70% or 80% of his or her portfolio-in passive investments is guilty of malfeasance, nonfeasance or some other kind of bad feasance!

To beat the market you'll have to invest serious bucks to dig up information no one else has yet.

But in practice, if often comes down to not suffering a loss as big as the huge gain you made a while ago.

As an economics undergraduate, I also worked on a part-time basis in Cambridge, Massachusetts, for a company that was advising customers about portfolio decisions, writing reports.

Everybody has some information. The function of the markets is to aggregate that information, evaluate it and get it incorporated into prices.

I should mention that I am a member of the board of directors of Dimensional Fund Advisors.

Most people might just as well buy a share of the whole market, which pools all the information, than delude themselves into thinking they know something the market doesn't.