Shares of software giant Symantec plunged more than 35% on Friday after the company announced it was conducting an internal investigation but did not give investors details.
The maker of Norton antivirus software lost $6 billion, or one-third, of its market value thanks to the selloff, which was the steepest decline in shares since the dot-com bubble in 2001, according to Reuters.
During an earnings call on Thursday, executives said the audit committee of the board had begun the investigation over concerns raised by a former employee. It did not say what those concerns were, only that they were not security-related.
The company has retained independent counsel and advisers.
Symantec “voluntarily” contacted the Securities and Exchange Commission and said that it cannot predict the outcome of the investigation but that results and guidance could be affected.
Nine analysts lowered their ratings on the company as of Friday, Reuters reported.