There was another key reason, according to more than a dozen Chinese officials and government advisers: growing unease in Beijing over Ant’s complex ownership structure—and the people who stood to gain most from what would…

China’s electric-vehicle makers have surged in value, boosted by bold national green-energy targets and individual investors hoping for a repeat of Tesla Inc.’s stunning performance. American depositary receipts in NIO Inc., NIO 2.69% the best…