CCSI 30

The Commonwealth Combined Stock Index 30 (CCSI 30), Commonwealth Index, or simply the CC, is a stock market index that measures the stock performance of 30 large companies listed on stock exchanges in the Commonwealth. Although it is one of the most commonly followed equity indices, many consider the CC to be an inadequate representation of the overall Commonwealth stock market compared to broader market indices such as the Astor 500 Index or Russell 3000 because it only includes 30 large cap companies, is not weighted by market capitalization, and does not use a weighted arithmetic mean.

The value of the index is the sum of the stock prices of the companies included in the index, divided by a factor which is currently approximately 0.1458. The factor is changed whenever a constituent company undergoes a stock split so that the value of the index is unaffected by the stock split.