Today's chart illustrates how the stock market has performed during the average post-election year. Since 1900, the stock market has tended to underperform from early January to late February and again from early August to early November during the average post-election year. Some parts of the year have, on average, outperformed. The most notable period of outperformance has occurred from late March to late May. In the end, however, the stock market has tended to underperform during the entirety of the post-election year. One theory to support this behavior is that the party in power will tend to make the more difficult economic decisions in the early years of a presidential cycle and then do everything within its power to stimulate the economy during the latter years in order to increase the odds of re-election.