Radhakishan Damani is the 61-year-old billionaire Founder of supermarket chain D-Mart, which recently went for IPO. On Tuesday, D-Mart's stock more than doubled by the closing, briefly taking Damani's net worth to $5.3 billion, making him richer than Reliance Group's Anil Ambani and Bajaj Group's Chairman Rahul Bajaj. While Damani holds 39.4% stake in D-Mart, his family owns 42.8% stake.