A number of studies have looked at such items as the "Super Bowl Indicator" -- i..e, the effect on the stock market of which division's team wins the Super Bowl. Others include the impact of a Triple Crown winner in horse racing. The newest one is the returns in the market during time periods when McDonald's is selling the McRib, versus when they are not. There is a strong correlation to returns, but this is obviously not causation. See article here (Of Dollars and Data).
