Sensex, India's first-ever stock market designed to track 30 biggest companies in the country, turns 40 on January 2. Over the years, the Sensex has seen massive growth, with 15,594% returns. Sensex 30 companies' combined market value is roughly $1.7 trillion, surpassing $845-billion total annual GDP of New Zealand, Hungary, Kuwait, and Morocco, reported Outlook Money, citing IMF data.