Friday's Early Winners & Losers

California Micro Devices(CAMD Quote) plummeted in after-hours trading Thursday when the semiconductor-products company lowered its first-quarter guidance.

For the quarter ended June 30, the company lowered its previous guidance by $2 million and now expects revenue of $15 million to $16 million, compared with $14.7 million a year ago. On a GAAP basis, the company expects to post a net loss of 12 cents to 13 cents, compared with earnings of 2 cents a share a year ago. Excluding items, the company is expecting earnings of 5 cents to 6 cents a share. Analysts polled by Thomson First Call are looking for the company to post earnings of 4 cents a share on revenue of $17.7 million.

"With the exception of our packaged EMI filter ASIPs and low capacitance ESD devices, we have seen a broad-based decline in demand for our products in the last month," said CEO Robert V. Dickinson. Shares dropped 97 cents, or 16.6%, to $4.89 in after-hours trade.

Medarex(MEDX Quote) stumbled after hours when the biopharmaceutical company said it had received a grand jury subpoena from the U.S. attorney's office in New Jersey, requesting documents and information related to its past stock-option grants and practices. The Princeton, N.J., company had received a similar request from the Securities and Exchange Commission. Medarex said it is cooperating with both investigations.

The company also said it has been notified of the filing of two shareholder derivative lawsuits in New Jersey state court that name Medarex and some of its current and former directors and officers as defendants. The lawsuits allege breach of fiduciary duty associated with Medarex's options-grant practices. They also allege violations of federal securities laws in connection with public statements made by Medarex in its SEC filings relating to its stock-option practices and related accounting. They seek unspecified damages and equitable relief. Shares were losing 51 cents, or 5.2%, to $9.30 after hours.