Only four stocks — Reliance Industries, Larsen & Toubro, ITC and Hindustan Unilever (then Hindustan Lever) — have survived the roller-coaster ride of the S&P BSE Sensex over the years. The BSE Sensex was launched on January 2, 1986 with 1978-79 as base year at a base value of 100 points. Since then, the benchmark has undergone various changes in its constituents. However, these four stocks stood rock solid and continued to survive over three decades.
The Sensex was earlier dominated by Tata and Birla group companies. Some of the companies such as Asian Cables, Zenith and Scindia Shipping have disappeared either through merger or were wound up.
1996: Major revamp
The Sensex went into a major overhaul in 1996 with the entry of new economy players, while Ballarpur Industries, Bharat Forge, Bombay Dyeing, Ceat Tyres, Century Spinning, GSFC, Hindutan Motors, Indian Organic, Indian Rayon (now Aditya Birla Nuvo), Kirloskar Cummins (now Cummins), Mukand Iron, Pelco Electronics (Phillips), Premier Automobiles, Siemens and Voltas were shunted out. Arvind Mills, Bajaj Auto, BHEL, BSES (Reliance Infra), Colgate Palmolive, Gujarat Ambuja Cement (Ambuja Cements), HPC, ICICI Bank, IDBI, IPCL, MTNL, SBI, SAIL and Tata Chemicals replaced those stocks in the Sensex.
Sensex, which earlier used to weight the stocks based on market-cap, shifted to free-float based market-cap in 2003. Instead of using a company’s total outstanding shares, it now uses non-promoter holding shares, which are readily available for trading.
In 2013, the BSE joined hands with S&P Dow Jones, for the S&P BSE Sensex venture. According to the terms of the collaboration, the S&P brand was used for Sensex and other indices of the BSE.