Topix Core 30 Index: What It is, How It Works

What Is the Topix Core 30 Index?

The Topix Core 30 Index is a market index composed of 30 of the largest companies out of the stocks listed on the First Section of Japan's Tokyo Stock Exchange, or Topix. The Topix Core 30 is one of several different Topix indexes.

The Topix Core 30 Index is meant to measure the performance of the 30 companies, which are both highly liquid and have the largest market capitalizations. The index is weighted by companies’ free floats.

Understanding the Topix Core 30 Index

The Topix Core 30 is an index of the 30 most liquid and highly capitalized stocks of the over 1,500 companies listed on the Topix index.

The name Topix is an acronym for Tokyo Stock Price Index, and Topix lists all Japanese companies of the Tokyo Stock Exchange’s First Section. Topix is one of two widely followed index families on the Tokyo Stock Exchange, the other being the Nikkei.

In terms of the method of calculation and the use of the index, the Topix indexes can be thought of as being similar to the S&P indexes used in the United States. The Nikkei index is most similar to the Dow Jones Industrial Average index in the United States.

The Topic Core 30 is an exchange-traded fund (ETF) of stocks chosen and weighted by market capitalization. The Topix Core 30 is managed by Nomura Asset Management and operated by the Tokyo Stock Exchange. Dividends are paid on July 15 of every year.

Because the Topix Core 30 focuses only on the top 30 stocks, it is indicative of the growth of the Japanese economy, but not of any market details, and it does not express any events or trends within industries or of the breadth or depth of the Japanese economy as a whole.

Change in Weighting

From 2005 through 2006 a change in the way companies were weighted in the Topix Core 30 was phased in. Previously companies were weighted by the total number of shares outstanding for the company. This privileged companies that had many shares, even if the company itself or its business partners owned most of those shares so they could not be traded.

The market transitioned to weighting companies by the number of shares they had available for trading. This is called “free float,” and it privileges companies that are available to trade for investors and traders. This change made the Topix Core 30 more democratic, accessible, and responsive to trading activities.