Mattson Technology Inc.'s stock dropped almost 17 percent Monday, erasing its gains for the year, after being downgraded Monday by CIBC World Markets.
Analyst Gary Hsueh cut Fremont-based Mattson (NASDAQ:MTSN) to sector underperformer from sector performer. He also cut his 2007 earnings estimate to 40 cents a share from 45 cents.
Mattson is losing business at Toshiba Corp. to rival San Jose-based Novellus Systems Inc. (NASDAQ:NVLS), Hsueh warned, and isn't getting as many orders from other companies.
The company's stock closed the day at $8.69 after hitting as low as $8.48.