India’s richest man surged past Silicon Valley tech titan Elon Musk as well as Alphabet Inc. co-founders Sergey Brin and Larry Page to become the world’s sixth-richest person.

The chairman of Reliance Industries Ltd., whose wealth surpassed Warren Buffett’s last week, is now worth $72.4 billion, according to the Bloomberg Billionaires Index. Shares of the conglomerate have more than doubled from a low in March as its digital unit got billions in investments from companies including Facebook Inc., Silver Lake and, most recently, Qualcomm Inc.

Indian billionaire Mukesh Ambani’s energy empire is slowly shifting to e-commerce, with tech giants seeking to take a piece of India’s fast-growing digital business. The world’s second most-populous nation has seen a spike of foreign interest in its economy, especially from Silicon Valley, and Google said on Monday it will spend $10 billion in the coming years to help accelerate the adoption of digital technologies in the country.

After a drop in U.S. tech shares on Monday, Page’s fortune now stands at $71.6 billion, while Brin’s is at $69.4 billion and Tesla Inc.’s Musk is worth $68.6 billion. Buffett’s net worth dropped last week after he gave away $2.9 billion to charity.