India's top industrialist Mukesh Ambani is no longer Asia's richest man, relinquishing the title to Jack Ma after oil prices collapsed along with global stocks.
The rout, exacerbated by mounting fears that the spread of the novel coronavirus will thrust the world into a recession, erased $5.8 billion from Mr. Ambani's net worth on Monday and pushed him to No. 2 on the list of Asia's richest people, according to the Bloomberg Billionaires Index. Ma, the Alibaba Group Holding Ltd. founder who relinquished the No. 1 ranking in mid-2018, is back on top with a $44.5 billion fortune, about $2.6 billion more than Ambani.

Oil plunged the most in 29 years on Monday as Saudi Arabia and Russia vowed to pump more in a struggle for market share. The slump comes just as the coronavirus is spurring the first decline in demand in more than a decade. That raises questions about whether Mr. Ambani's flagship Reliance Industries Ltd. will be able to cut net debt to zero by early 2021, as he has pledged. The plan hinges on a proposal to sell a stake in the group's oil and petrochemicals division to Saudi Arabian Oil Co., the world's biggest crude producer.

While the coronavirus has curtailed some of the tech giant Alibaba's businesses, the damage has been mitigated by increased demand for its cloud computing services and mobile apps.

Reliance Industries, by comparison, has no such silver lining. The Indian conglomerate's shares plunged 12% on Monday, the most since 2009, extending this year's decline to 26%. Alibaba's American depositary receipts have slipped 6.8% so far in 2020.