Impact:
Dow Jones stock index
The Dow Jones stock index is the oldest stock index in the world, and its full name is the average stock price. Prepared by charles dow, founder of Dow Jones Company, on 1884. Its original Dow Jones stock price average index is based on 1 1 representative railway companies, calculated and compiled by arithmetic average method, and published in the Daily Communication edited and published by charles dow himself. Its calculation formula is:
Average share price = the sum of the prices of the selected stocks. Starting from 1897, the Dow Jones average stock price index is divided into two categories: industry and transportation, in which the industrial average stock price index includes 12 stocks and the transportation average index includes 20 stocks, which are published in the Wall Street Journal published by Dow Jones Company. 1929, the Dow Jones stock price average index added utility stocks, making it include 65 stocks, which have continued to this day.
At present, the average Dow Jones stock price index is based on 1928 65438+ 10/month. Because the average price of Dow Jones stock at the close of this day is about 100, it is set as the benchmark date. In the future, the percentage calculated by comparing the stock price with the benchmark date becomes the voting price index of each period, so the current stock index is generally based on points, and the rise and fall of each point of the stock index is the percentage of the rise and fall relative to the benchmark date.
The initial calculation method of Dow Jones stock price average index is simple arithmetic average method. When the stock is ex-dividend, the stock index will be discontinuous. After 1928, the Dow Jones stock average price index was changed to a new calculation method, that is, the connection technology was adopted when the stock was ex-dividend or ex-dividend, so as to ensure the continuity of the stock index, make the stock index more perfect and gradually spread to the whole world.
At present, the Dow Jones stock price average index is divided into four groups. The first group is the average index of industrial stock prices. It is composed of 30 representative stocks of large industrial and commercial companies, which become larger with the development of economy, and can roughly reflect the price level of the entire industrial and commercial stocks in the United States, which is also the average price of Dow Jones Industrial Stock that people usually quote. The second group is the average stock price index of the transportation industry.
Including the shares of 20 representative transportation companies, namely, 8 railway transportation companies, 8 airlines and 4 road freight companies. The third group is the average share price index of public utilities, which consists of 1 5 stocks of gas companies and power companies representing American public utilities. The fourth group is the average price composite index.
It is a comprehensive index composed of 65 stocks in the first three groups of stock price average indexes. Although this group of comprehensive indexes provides direct stock market conditions for dominant stocks, the first group-industry stock price average index is usually cited now.
Dow Jones average stock price index is the most influential and authoritative stock price index in the world at present. One of the reasons is that the stocks selected by the Dow Jones average share price index are representative, and the issuing companies of these stocks are all famous companies with important influence in the industry. Their share prices have attracted the attention of the world stock market, and investors from all countries attach great importance to them. In order to maintain this feature, Dow Jones often adjusts the stocks selected by its stock price average index, and replaces those stocks that lose their representativeness with dynamic and more representative company stocks. Since 1928, 30 kinds of industrial and commercial company stocks used only to calculate the average price index of Dow Jones Industrial Average have been replaced 30 times. Almost every two years, the stock of a new company will replace the stock of the old company. The second reason is that The Wall Street Journal, the news media that publishes the Dow Jones stock price average index, is the most influential newspaper in the world financial circle.
The newspaper reported in detail the average index, percentage change rate of each sample stock and the turnover of each sample stock calculated every hour every day, and paid attention to the stock price average index after share split's correction. During the business hours of the new york Stock Exchange, the Dow Jones average stock price index is published every half hour. The third reason is that this average stock price index has never stopped since its compilation, and it can be used to compare the stock market and economic development in different periods. It has become one of the most sensitive average stock price indexes reflecting the changes in the American stock market, and it is the main reference for observing market dynamics and engaging in stock investment. Of course, because dow jones stock price indexes is a constituent stock index, it only includes a very small part of more than 2,500 listed companies, and most of them are active stocks, excluding companies in the service industry and financial industry that have developed rapidly in recent years, so its representativeness has been questioned and criticized by people.
Standard & Poor's stock price index
In addition to dow jones stock price indexes, the Standard & Poor's share price index is also very influential in the United States. It is the stock price index compiled by Standard & Poor's Company, the largest securities research institution in the United States. The company began to compile and publish the stock price index on 1923. Initially, 230 stocks were selected and two stock price indices were compiled. By 1957, the range of this stock price index has expanded to 500 stocks, divided into 95 combinations. The four most important groups are industrial group, railway group, public utility group and 500-share mixed group. From 1 July 9761,it was changed to 400 industrial stocks, 20 transportation stocks, 40 public utilities stocks and 40 financial stocks. For decades, although the stock has changed, it has always remained at 500. Standard & Poor's stock price index is based on the average market price of sample stocks from 194 1 to 1943, weighted by the number of listed stocks, and weighted by the base period, and its base is 10. Take the current stock market price multiplied by the number of shares issued in the stock market as the numerator, the base stock market price multiplied by the number of shares in the base period as the denominator, and the divided number multiplied by 10 as the stock price index.