“Weak EMH” is the claim that you can’t systematically exploit market irrationalities to make money. Weak EMH has actually held up pretty well.
There are people who make money off of, say, arbitrage against foreign currencies. Someone has to be keeping the rates in line when they go off slightly. The problem is that you need huge amounts of capital to do this effectively, so it’s limited to institutional investors.
There are people who make money off of, say, arbitrage against foreign currencies. Someone has to be keeping the rates in line when they go off slightly. The problem is that you need huge amounts of capital to do this effectively, so it’s limited to institutional investors.