Nobody sensible believes that financial markets are perfectly efficient.
On the other hand, nobody sensible believes they are completely inefficient, or trivially beatable. If you want evidence of this, feel free to go out and beat the market with long plays on the alpha you imagine you have.
I think it's usually helpful, when trying to understand the world, to think, "markets are pretty efficient, do they agree with me? If they don't, can I think of a real reason why this may be a case where they're wrong, or am I just engaging in wishful thinking?"
I think it is not usually helpful, when trying to understand the world, to be really mad about the EMH.
On the other hand, nobody sensible believes they are completely inefficient, or trivially beatable. If you want evidence of this, feel free to go out and beat the market with long plays on the alpha you imagine you have.
I think it's usually helpful, when trying to understand the world, to think, "markets are pretty efficient, do they agree with me? If they don't, can I think of a real reason why this may be a case where they're wrong, or am I just engaging in wishful thinking?"
I think it is not usually helpful, when trying to understand the world, to be really mad about the EMH.