Comment by eru

> If a journalist made random predictions, how would you know?

If they consistently randomly get lucky, that's fine. Just check multiple stories to get a sense of the distribution.

> If a journalist made a random prediction, and market participants believed the prediction, so the market then did what the journalist predicted, how would you know?

If all you care about whether the prediction is accurate (so you can trade on it), you don't need to worry about the philosophical differences between an accurate prediction and a self-fulfilling prophecy.