Bankrupt car rental firm Hertz has shelved plans to issue up to $500 million in new stock, after the Securities and Exchange Commission raised concerns and launched a review into the deal.

In a regulatory filing Wednesday, Hertz disclosed that it is suspending the stock offering after the SEC informed the company that it would be investigating the deal. Despite filing for Chapter 11 bankruptcy in May, a judge in Delaware last week approved Hertz’s plan to raise fresh liquidity by issuing new shares.

Hertz’ stock performance has been one of the most fascinating stories on Wall Street this year. Even after filing for bankruptcy protection and seeing its most famous shareholder, Carl Icahn, throw in the towel on the company, Hertz’s shares spiked to as high as $5.53 each this month.

The rebound has been widely attributed to an influx of interest in the company from retail investors—many of whom have turned to the stock market during the coronavirus pandemic, hoping to ride the market’s impressive rally since March. The fact that stockholders are among the last in line to get paid when a company files for bankruptcy—behind bondholders and other creditors—has not discouraged investors from trading the stock at market-high volumes in recent weeks.

Hertz acknowledged the risk that equity investors would be taking, warning them in offering documents that the stock could potentially be “worthless” given the company’s financial position. But the company appeared intent on pushing ahead with the issuance, presumably to capitalize on the interest its existing shares have garnered on the market.

The news that Hertz is suspending the issuance amid the SEC’s investigation saw trading of the company’s stock temporarily halted on the New York Stock Exchange on Wednesday afternoon. Hertz’s shares closed the day’s trading at $2 per share, up 2.6% on the day.