Even a $500 million buyback wasn’t enough to save online lender Qudian Inc. from a massive selloff of its New York-listed stock and the first in what’s likely to become a flood of shareholder lawsuits.

The company was a rising star when it listed in 2017, raising nearly $1 billion and becoming one of the first firms from China’s then-hot fintech sector to go public. But times have been much tougher over the last two years as Beijing clamps down of a noisy group of high-tech financiers that often have laxer lending standards and weaker risk-prevention systems than traditional banks.

That crackdown was front and center in a company announcement issued late Thursday, in which Qudian formally withdrew its previously issued 2019 guidance, citing “uncertainty related to the recent regulatory and operating environment.” It noted that the broader lending market had become more cautious, with the result that its “transaction volumes in loan facilitation and on the open platform have decreased substantially.”

In a bid to stop the inevitable sell-off, the company concurrently announced a $500 million share buyback to boost confidence. But investors were buying none of that, and Qudian’s shares tanked nearly 20% to a new all-time low when the bloodbath was finished. At their current level they now trade at less than one-sixth of their IPO price from headier times.

It didn’t take the sharks long to detect the scent of blood. Just eight hours after the announcement — the length of the trading day — the law firm Pomerantz LLP announced it was investigating claims that the company duped its shareholders. Things will probably get worse before they get better, as more such shareholder lawsuits are almost certain to pile in.

Contact reporter Yang Ge (geyang@caixin.com; twitter: @youngchinabiz)

Related: China Merchants Bank Executive Arrested in Connection to P2P Business