The individual traders' guesses are influenced by the market and by their prior knowledge on how similar stocks of similar companies performed. So the final ave

The individual traders' guesses are influenced by the market and by their prior knowledge on how similar stocks of similar companies performed. So the final average does depend on the values of other stocks in some ineffable fashion. Whether or not that's the "correct" price of the stock might be largely a question of whether or not you accept trader intuition as axiomatic or not.