Very good point. Since you made a comparison to prediction markets, let's focus on earnings release dates. Earnings release is an event that's known to happen

Very good point. Since you made a comparison to prediction markets, let's focus on earnings release dates. Earnings release is an event that's known to happen on a certain date in the future, just like some political election (only few companies don't disclose their future earnings dates in advance, Berkshire Hathaway is amongst them). There are plenty of studies researching option prices and the stock moves post earnings release, this is just one of them: https://www.stern.nyu.edu/sites/default/files/assets/documents/NYU%20conference%20Johannes%20final.pdf https://www.stern.nyu.edu/sites/default/files/assets/documen... The conclusion of that particular study is that option prices prior to the earnings release date are helpful for learning about the future stock price volatility.