[variaga]

Even if the EMH were true, it only says "_IF_ a market is efficient, THEN all <modifier depending on the EMH version> information is included in the price."

The EMH does not imply that any particular market is efficient, and if the market isn't efficient, the EMH doesn't apply.

Lots of people do appear to assume the axiom "All markets are efficient", but that is plainly incorrect.

[perl4ever]

I think there was some nobel prize winning refinement to the theory that basically said markets approach theoretical efficiency in the limit as transaction costs go to zero, and interesting deviations from efficiency happen because transaction costs are not zero. Like, the whole reason we have firms and markets in real life is because zero transaction costs don't exist globally and so it helps to have ways to reduce them here and there.