In the Back To The Future trilogy, the bad guy is a bully called Biff Tannen.
The megalomaniac mogul amassed his wealth because his older self travelled back in time to give his younger self the Grays Sports Almanac, a compilation of every sports result from 1950 to 2000. So Biff was able to earn a spectacular fortune from sports betting.
Financial markets – with their twists and turns and unknowability – remind us just how hard it is to predict the future and just how wonderful perfect foresight would be.