The principles seem pretty simple actually and have been known for a long while. Farma's dissertation was published in 1965 and concluded that stock price movements are unpredictable and random.

Given what I read in the papers and hear on TV there must be a very large number of people in the financial markets who disagree with the premise however.

The efficient market hypothesis is that the stock markets already reflect all information that is possible to know.

I have never been much interested in investing and finance as it seems so tedious to me. But this idea I find rather intriguing.