The , more commonly called the Nikkei, the Nikkei index, or the Nikkei Stock Average (ˈnɪkeɪ, /ˈniːkeɪ/, or /nɪˈkeɪ/), is a stock market index

Stock market index

A stock market index is a method of measuring a section of the stock market. Many indices are cited by news or financial services firms and are used as benchmarks, to measure the performance of portfolios such as mutual funds....

 for the Tokyo Stock Exchange

Tokyo Stock Exchange

The , called or TSE for short, is located in Tokyo, Japan and is the third largest stock exchange in the world by aggregate market capitalization of its listed companies...

 (TSE). It has been calculated daily by the Nihon Keizai Shimbun

Nihon Keizai Shimbun

is one of the largest media corporations in Japan. Nikkei specializes in publishing financial, business and industry news. Its main news publications include:* Nihon Keizai Shimbun , a leading economic newspaper....

 (Nikkei) newspaper since 1950. It is a price-weighted average (the unit is yen

Japanese yen

The is the official currency of Japan. It is the third most traded currency in the foreign exchange market after the United States dollar and the euro. It is also widely used as a reserve currency after the U.S. dollar, the euro and the pound sterling...

), and the components are reviewed once a year. Currently, the Nikkei is the most widely quoted average of Japanese equities, similar to the Dow Jones Industrial Average

Dow Jones Industrial Average

The Dow Jones Industrial Average , also called the Industrial Average, the Dow Jones, the Dow 30, or simply the Dow, is a stock market index, and one of several indices created by Wall Street Journal editor and Dow Jones & Company co-founder Charles Dow...

. In fact, it was known as the "Nikkei Dow Jones Stock Average" from 1975 to 1985.

The Nikkei 225 began to be calculated on September 7, 1950, retroactively calculated back to May 16, 1949. Since January 2010 the index is updated every 15 seconds during trading sessions.

The Nikkei 225 Futures, introduced at Singapore Exchange

Singapore Exchange

Singapore Exchange Limited is an investment holding company located in Singapore and providing different services related to securities and derivatives trading and others. SGX is a member of the World Federation of Exchanges and the Asian and Oceanian Stock Exchanges FederationSingapore Exchange...

 (SGX) in 1986, the Osaka Securities Exchange

Osaka Securities Exchange

is the second largest securities exchange in Japan, in terms of amount of business handled. As of 31 December 2007, the Osaka Securities Exchange had 477 listed companies with a combined market capitalization of $212 billion. The Nikkei 225 Futures, introduced at the Osaka Securities Exchange in...

 (OSE) in 1988, Chicago Mercantile Exchange

Chicago Mercantile Exchange

The Chicago Mercantile Exchange is an American financial and commodity derivative exchange based in Chicago. The CME was founded in 1898 as the Chicago Butter and Egg Board. Originally, the exchange was a non-profit organization...

 (CME) in 1990, is now an internationally recognized futures index.

The Nikkei average has deviated sharply from the textbook model of stock averages which grow at a steady exponential rate. The average hit its all-time high on December 29, 1989, during the peak of the Japanese asset price bubble

Japanese asset price bubble

The was an economic bubble in Japan from 1986 to 1991, in which real estate and stock prices were greatly inflated. The bubble's collapse lasted for more than a decade with stock prices initially bottoming in 2003, although they would descend even further amidst the global crisis in 2008. The...

, when it reached an intra-day high of 38,957.44 before closing at 38,915.87, having grown sixfold during the decade. Subsequently, it lost nearly all these gains, closing at 7,054.98 on March 10, 2009—81.9% below its peak twenty years earlier.

Another major index for the Tokyo Stock Exchange is the Topix

TOPIX

Tokyo stock Price IndeX, commonly known as TOPIX, along with the Nikkei 225, is an important stock market index for the Tokyo Stock Exchange in Japan, tracking all domestic companies of the exchange's First Section. It is calculated and published by the TSE...

.

On March 15, 2011, the second working day after the massive earthquake in the northeast part of Japan

2011 Tōhoku earthquake and tsunami

The 2011 earthquake off the Pacific coast of Tohoku, also known as the 2011 Tohoku earthquake, or the Great East Japan Earthquake, was a magnitude 9.0 undersea megathrust earthquake off the coast of Japan that occurred at 14:46 JST on Friday, 11 March 2011, with the epicenter approximately east...

, the index dropped over 10% to finish at 8605.15, a loss of 1,015 points. This put it at its lowest close since March 10, 2009.

Weighting and modifications

Stocks are weighted on the Nikkei 225 by giving an equal weighting based on a par value of 50 yen per share. Events such as stock splits, removals and additions of constituents impact upon the effective weighting of individual stocks and the divisor. The Nikkei 225 is designed to reflect the overall market, so there is no specific weighting of industries.

Changes to the components

Stocks are reviewed annually and announcements of review results are made in September. Changes, if required, are made at the beginning of October. Changes may also take place at any time if a stock is found to be ineligible (e.g., delisting). All proposed changes will be announced in Nikkei's Japanese newspapers and will appear on NNI.

After a stock has been replaced, the divisor is reviewed and modified to ensure a smooth transition of the stock index.

Components

As of April 2011, the Nikkei 225 consists of the following companies: (Japanese securities identification code in parentheses)

External links

• Nikkei 225 constituents
• Nikkei 225 index on Yahoo! Finance
• Nikkei 225 index on Google Finance
• Nikkei 225 profile at Wikinvest