It's been a good year for Asia's richest man, Mukesh Ambani.

The Indian tycoon added almost $18 billion to his wealth — the most in Asia — taking his net worth to $61.9 billion, according to the Bloomberg Billionaires Index. In comparison, Alibaba Group Holding Ltd. founder Jack Ma's net worth grew $11 billion, while Jeff Bezos lost $13.6 billion.

The surge in Ambani's fortune this year was fueled by a 40 percent jump in the shares of his Reliance Industries Ltd., a conglomerate that's pivoting more toward consumer offerings than its core oil refining and petrochemicals businesses. The rally in the stock is almost triple the gains for India's benchmark S&P BSE Sensex index.