Project Summary
In this project, our team tested this hypothesis: If the President of the United States influences the stock market, we would expect the frequency of positive or negative close days, measured from election day to inauguration day and by total term of each President, to be greater than the market historical average.
We tested our hypothesis using the Dow Jones Industrial Average Index from January 3, 2001 through September 27, 2019.
To begin, here's a readily available chart of the Dow Jones Industrial Average Index over the past 100 years. Source: Dow Jones 100 Year Historical Chart
Dow Jones Industrial Average Index 100 years
Because our project focuses on the last 20 years, here's a similar chart for the Dow Jones Industrial Average Index over the past 20 years.
Dow Jones Industrial Average Index 20 years
For details on the following charts, click on the corresponding chart title on the "Plots" link above.
This is our version of the 20-year chart, color-coded by Presidential term.
Daily Close
Conclusion: Based on this data, we failed to reject the null-hypothesis, which was: If the President of the United States does not influence the stock market, we would expect the frequency of positive and negative close days, measured from election to inauguration and by total term of each President, to be equal to the market historical average.