His fortune has jumped by more than 80% as shares of flagship Piramal Enterprises soared in the past year, buoyed partly by the news of a restructuring that will involve the financial-services business being spun off and listed separately. Piramal has a board seat at Tata Sons, holding outfit of the Tata conglomerate, in which fellow billionaire Pallonji Mistry (No. 5) has a stake.