“Ant Group’s valuation may plunge further if its payment unit is forced to break up due to potential anti-trust probes by China’s central bank,” Chan wrote in a research note.

The revised estimate for Ant is a far cry from valuations that ran as high as $320 billion before the company was forced to scrap its record initial public offering in November. China’s crackdown forced Ma’s firm to withdraw the $35 billion IPO just days before its planned listing in Hong Kong and Shanghai.

China’s central bank said on Wednesday that any non-bank payment company with half the market share for online transactions, or two entities with a combined two-thirds share could be subject to antitrust probes.

If a monopoly is confirmed, the central bank can suggest the cabinet impose restrictive measures including breaking up the entity by its business type. Firms already with payment licenses would have a one-year grace period to comply with the new rules, the central bank said.

Alipay, with about 1 billion users, controls 55% of the mobile payments market. A break up could reduce its 600 billion yuan valuation in half, Chan said, adding it’s questionable whether Ant can relaunch its IPO this year.

Alibaba Group Holding Ltd., which holds a stake in Ant, fell for a second day in Hong Kong, dropping 2.9% at 9:57 a.m. The shares jumped 8.5% on Wednesday after Ma emerged in public for the first time since China began clamping down on his businesses, ending several months of speculation over his whereabouts.