Sensex will turn 40 years old on January 2, 2026, delivering a staggering 15,594% return on investments, according to a Times Now calculation. Introduced at 549 points in 1986, Sensex has seen as high as 60% annual volatility over the years. Despite that, estimates show that ₹10,000 invested in Sensex in 1986 would've become worth ₹15.7 lakh in 2025.