The "Super Bowl Indicator" is widely known, as the winner of the Super Bowl has been correlated to overall stock market performance. While this does not imply causation, is does make for an interesting discussion of market efficiency. A similar item is the performance of the stock market in years when a horse wins the Triple Crown--the results are not good. So, many people may be watching how California Chrome does in the upcoming Belmont Stakes. See article here, WSJ.
Dolvin, Steven D., "Triple Crown and the Stock Market" (2014). All Chapters. 102.