DMart Founder Radhakishan Damani's net worth has surged 11% this year to $10.7 billion, making him the biggest gainer among the 12 richest Indians whose wealth is tracked by Bloomberg. Serum Institute of India's Cyrus Poonawalla was the only other Indian tycoon among the 12 whose wealth rose in 2020. Poonawalla's wealth rose by 2.6% to $8.9 billion this year.