Updated from 2:53 p.m. EDT with new stock prices

Tech stocks plunged Monday , along with major market indices, on weak economic data and executive shake-ups at two major banks.

Open-source based IT security company Sourcefire ( FIRE) was up 19 cents, or 2.5%, to $7.83. Sourcefire rejected a $7.50 a share, or $188 million, hostile buyout bid by private IT security company Barracuda Networks on Friday, saying it undervalues the company.

Palm ( PALM) was up 39 cents, or 6.4%, to $6.45. The gains were based on an IDC smartphone market share report Friday that said Palm took 13.4% of smartphone sales in the first quarter of 2008, up from 7.9% in the fourth quarter, based on strong sales of its Centro smartphone. A report in the blog Engadget also suggested that Palm's upcoming Treo 800W may be making its debut on Verizon's ( VZ) wireless network soon.

Shares of TiVo ( TIVO) were down 76 cents, or 9%, to $7.65 as the company continued to battle with Dish Network ( DISH) and EchoStar ( SATS) over patents. Dish and Echostar filed a lawsuit against TiVo Friday asking a Delaware court to find that their new DVR software does not infringe Tivo's patent. The lawsuit is in response to Tivo's public statements that our new DVR software infringes its patents, said Dish Network in a statement Friday.

Apple ( AAPL) shed $2.62, or 1.4%, to $186.13, although an analyst from Thomas Weisel raised his price target for the stock to $225 from $195 based on increased confidence that Apple is on track to exceed Street expectations for fiscal 2008 and 2009.

Microsoft ( MSFT) was down 53 cents, or 1.9%, to $27.79. Microsoft said it has partnered with Hewlett-Packard ( HPQ) to install its Live Search toolbar on all H-P computers shipping in North America from January 2009. The deal will make Microsoft's search service the default search engine setting in all browsers on H-P PCs. Shares of Yahoo! ( YHOO) were down 40 cents, or 1.5%, to $26.36. Microsoft's deal with H-P could hurt Yahoo!, which has been the default search engine for browsers on H-P computers.