Chipmakers are having a terrible day in the stock market

• Semiconductor stocks fell on Tuesday as Super Micro Computer and AMD and Super Micro led a sell-off.
• Super Micro tanked as much as 34% after its auditor resigned.
• AMD fell more than 10% after revenue guidance disappointed investors.

It's a rough day to be a semiconductor stock.

The Philadelphia Stock Exchange Semiconductor Index tumbled 3% on Wednesday, led by plunges in Super Micro Computer and Advanced Micro Devices.

Super Micro tanked as much as 34% after its auditor, Ernst & Young, resigned from working with the firm.

"We are resigning due to information that has recently come to our attention which has led us to no longer be able to rely on management's and the Audit Committee's representations and to be unwilling to be associated with the financial statements prepared by management," the accounting firm said in a filing.

The firm is reportedly under investigation by the Department of Justice after a scathing report from Hindenburg Research targeted the company, alleging that it has poor internal accounting controls.

In perhaps a more ominous sign for the broader chipmaking sector, AMD slid as much as 10% at intraday lows after the company's fourth-quarter guidance came in below analyst expectations.

"The next few quarters going into 2025, I think we expect that the environment will continue to be tight, but we've also planned for significant growth going into 2025," CEO Lisa Su said during the firm's conference call.

That weakness bled into other major chipmaker stocks, with Nvidia, Broadcom, and Intel also sliding as much as 2% at lows.