Getting into deeper theory now. Is the EMH dependent on the number of participants? It most certainly is contingent on the flow of information. But even then, we see the EMH at play with regard to startups in the VC stage: After correcting for risk, they don't make any more money. I argue that these companies are in a pre-market stage.

Then again, my argument is not contingent on the efficiency of any one price. If you invested a little bit in everything that pops up in your inbox and after five years gives you a risk-adjusted return higher than the average market I'd be highly surprised. So I'd be willing to accept that there are plenty of inventions and products in the pre-market stage that are wrongly priced, but as a whole the price is very correct near zero.