Supermicro (NASDAQ:SMCI), a well-known AI server maker, saw its stock price plunge on Thursday following reports of a Justice Department investigation into alleged accounting irregularities. The investigation follows a critical report by activist short-selling firm Hindenburg Research that accused the company of accounting manipulation and other problems.

The Wall Street Journal, citing unnamed sources, reported that the Justice Department has opened an investigation into Super Micro Computer. The news sent SMCI shares plunging more than 14% to 392.18, hitting an eight-month low in intraday trading.

The company’s problems began in August when Hindenburg Research released a report alleging accounting manipulations, export control failures and customer problems. Since then, Supermicro has delayed filing its annual report with the Securities and Exchange Commission, citing the need for additional time to evaluate its internal controls over financial reporting.

This series of events has resulted in a significant decline in Supermicro’s stock performance. The stock has lost over 30% of its value since the end of August. The company’s Relative Strength Rating has also suffered, falling from a perfect 99 three months ago to a current rating of 27, according to MarketSurge.

As Supermicro faces increasing scrutiny, investors and industry observers are monitoring the situation closely and waiting to see how these developments will impact the company’s future in the competitive AI server market.

This article first appeared on GuruFocus.