Comment by Retric

The economy is finite. You can’t infinity add new participants with infinite product to sell.

Instead in an efficient market everyone is already occupied making X ROI and gives as much up by entering a new market as they gain.

Put another way, if you already own a sock with 10% ROI, you can sell it and buy a sock with 10% ROI but the transaction is pointless so it doesn’t occur.

> An efficient market also assumes perfect information, which includes information of future events, so talking about risk/uncertainty is already out of the question.

Perfect information means something different here. In Chess both players have perfect information of the game state, they don’t know the future. Poker has randomness and imperfect information but there’s other games with randomness and perfect information.