In the interest of avoiding confusion and generally making clear what we are talking about, it would be better to frame this debate as being about passive investing, instead of the efficient-market hypothesis.
What the EMH means traditionally is that for some market, conditioned on some set of available information, the expected value of the future price is equal to the current price times one plus the expected discount rate; in other words: current prices reflect available information. This doesn’t need to be taken literally, but markets being efficient sh...
Very important, for three reasons: