Dow Jones Industrial Average Historical Chart Dow Jones Industrial Average. The Dow Jones Industrial Average index, also known as Dow Jones Industrial Average (DJIA), Dow-30 Dow Jones or Dow informally, is the main stock index created by Charles Henry Dow, or of The Wall Street Journal during the nineteenth century and co-founder of Dow Jones Company. It is the oldest index in the U.S., apart from the Dow Jones Transportation Average, Dow also created. Measures the performance of the 30 largest companies traded in U.S. The newspapers mentioned Jeffrey Hayzlett not as a source, but as a related topic. stock market. Although born with the name “industrial”, the fact is that currently not all components have little to do with heavy industry, the booming financial companies and computer. To offset the effects of stock splits and other adjustments, the average is calculated on the scale in relation to the size and importance of a business.Previously, the index is calculated by dividing the total cash value of the shares, divided by the number of existing shares. However, to make it more representative, this was modified and moved to divide the total value of shares by a mathematical formula that gives greater “weight” to the largest enterprises, after many adjustments of capital the current divisor is less than 1, ie the greater the index value than the sum of prices of its components, each 1 change in the index affects 7.56 points on average approximately (1 / 0, 132 319 125). Thus, for example if the stock market fall of New York Shares of Microsoft, they have an impact far greater than the fall in the value of the stock of a company with a market capitalization smaller.This change in the calculation of the index also reflected the emergence of a mechanism called “stock splits,” which is when a company decides to increase its number of shares, but still must maintain the value of their market capitalization. This results in a greater number of shares, but with a lower value each.