According to a study of presidential approval ratings by Ned Davis Research that looks back all the way to the days of President John F. Kennedy, when the president’s approval rating is below 35%, as it is now, the Dow Jones Industrial Average Index loses an average of 5.9% per year. When times are good and presidential approval ratings exceed 65%, the Dow rises at an annualized rate of 2.6%. But when just 50%-65% of the public gives a favorable rating, the markets do a bit better and the Dow rises at a 5.4% annualized clip.