SENSEX

The Sensex (S&P BSE Sensex) is the benchmark index of the Bombay Stock Exchange — 30 of the largest and most actively traded companies listed on the BSE, weighted by free-float market capitalisation. It is India’s oldest equity index, published since 1986.

Both track Indian large-caps and move closely together; the Sensex tracks 30 companies on the BSE while the Nifty 50 tracks 50 companies on the NSE, so the Nifty spreads the same idea across a somewhat broader list.