you're wrong about the mechanism - it's not that the thinking is the cause of the efficiency. It's the large number of participants all doing their own brand of thinking, and that the _average_ of all of those approaches the "correct" price. It requires the large number of participants because for such an average to approach "correct", errors within each participant's guesses cancel each other out.

And the immediacy comes from the large amount and speed of the transactions. It does not require that these participants sus out the correct value from information - they could've actually just guessed.