Data source: YCharts

What: According to data from S&P Capital IQ, Marvell Technology(NASDAQ:MRVL) stock fell 19.7% after the company disclosed in a regulatory filing that it is conducting an internal investigation into some of its accounting and control measures for revenue recognition. On top of that, it announced poor preliminary fiscal second quarter results and encountered several other challenges along the way. 

So what: Things started off poorly in September for Marvell, and then went from bad to worse. In a regulatory filing at the beginning of the month, Marvell said that it would conduct an "investigation of certain revenue recognition issues in the second quarter of fiscal 2016 and any associated issues with whether senior management's operating style during the period resulted in an open flow of information and communication to set an appropriate tone for an effective control environment."

Specifically, the company is looking at 7% to 8% of revenue that was recognized in the fiscal 2016 second quarter that "would have been received and earned in the third quarter of fiscal 2016 and is now no longer available for receipt in that quarter."

That announcement was enough to topple the stock, but the same filing also noted that revenue in the fiscal second quarter would be $711 million -- a 26% decline year-over-over. It also fell far short of the $722 million analysts were expecting.

Then, toward the end of the month, it failed to find a buyer for its mobile business and announced it would lay off 17% of its global workforce. 

Now what: Marvell's internal investigation is ongoing, and investors will have to wait a while to see how that all plays out. For now, the bigger news is Marvell jettisoning the mobile chipset and cellular baseband business. 

Marvell initially thought it could sell its mobile business, but that didn't quite work out. It's not all that surprising that Marvell's leaving this segment, considering that it was the smallest out of the top cellular baseband players and competed head-on with juggernauts like Qualcomm. And its exit from the cellular mobile chip business follows in the recent footsteps of Broadcom, NVIDIA, and others.

The company still has a long road ahead as it winds down its mobile business and awaits the conclusion of its internal accounting investigation. Investors sticking with the company should prepare for more volatility in the near future. 

Chris Neiger has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Qualcomm. The Motley Fool recommends Nvidia. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.