BSE Sensex or Bombay Stock Exchange Sensitive Index is a value-weighted index composed of 30 stocks that started January 1, 1986. The Sensex is regarded as the pulse of the domestic stock markets.
The Bombay Stock Exchange SENSEX also referred to as BSE 30 is a free-float market capitalization-weighted index of 30 well-established and financially sound companies listed on Bombay Stock Exchange. The 30 component companies which are some of the largest and most actively traded stocks, are representative of various industrial sectors of the Indian economy. Published since January 1, 1986, the SENSEX is regarded as the pulse of the domestic stock markets in India.
The base value of the SENSEX is taken as 100 on April 1, 1979, and its base year as 1978-79. On 25 July, 2001 BSE launched DOLLEX-30, a dollar-linked version of SENSEX. As of 21 April 2011, the market capitalisation of SENSEX was about 
29,733 billion (US$663 billion) (42.34% of market capitalization of BSE), while its free-float market capitalization was 15,690 billion (US$350 billion).
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