Understanding the Dow is an essential part of building and increasing your investment portfolio. To calculate the Dow Jones Industrial Average (DJIA), you must divide the sum (component stock prices) by the Dow divisor. The Dow is influenced by several factors including supply and demand, natural disasters, wars, political conflicts, and policies for finances and economics. To educate yourself on investing, you should read books and enroll in courses, and always listen to your head and make sound choices instead of making emotional choices. Diversifying your stock portfolio with different industries is another smart strategy in case one specific industry takes a negative turn. Take time to research the Dow so you will understand more about the stock market and increase your investment portfolio.