With billions on the line, China halts Ant Group's IPO; Jack Ma summoned

The move upends what had been one of China's biggest business success stories

It was heralded as China’s answer to JPMorgan -- a homegrown financial giant on the cusp of the biggest stock-market debut the world has ever seen.

Instead, with billions on the line and an initial public offering all but sealed, Chinese authorities have abruptly thrown into doubt the future of Ant Group Co. and its celebrated founder, the billionaire Jack Ma.

Only days before the financial-technology juggernaut was to go public in Shanghai and Hong Kong -- a coup for China’s financial markets that once would have been unimaginable -- the $35 billion IPO was halted on Tuesday after Ma, China’s richest