Yeah, that statement is pretty loaded, the subject of dozens pf PHD dissertations alone.

I do think Fred is right, but it requires looking looking at the EMF in a slightly different way than most people understand it.

The market is 99% efficient. 1% is what could give some traders who have real skill an edge, such as the Warren Buffets and like. Most people would agree the markets are mostly efficient in that the market react to news quickly, and that most people who try to beat the market using a 'system' (fundamental analysis, quantitative analysis, technical analysis, or other) fail to do so.

But my interpretation of the EMH doesn't preclude the possibility that markets can occasionally exhibit inefficient behavior. It's just that the inefficiencies, when they arise, aren't big enough or occur consistently enough to allow the aggregate of firms to beat some 'rate' of return. This rate could be the risk free interest rate or the S&P 500 dividend yield, or some other benchmark. The EMH is predicated upon random-walk theory, in which theoretically any 'walk' is possible, including even a perfectly strait line for a near-infinite duration of time.