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FireEye buys Mandiant; GM & Ford expecting strong December sales; Micron downgraded; Martha & Macy's make up

Hot Stock Minute

Here are five stocks the Yahoo Finance team is following for you today.

First up is FireEye (FEYE), whose stock jumped close to 23% in after-hours trading yesterday. Why the surge? The computer security firm announced it will acquire rival, Mandiant Corp. for $1.05 billion in cash and stock. FireEye says it now expects the combined revenue to grow about 50% this year. FireEye started the year on a down-note, dropping almost 6% in regular trading, but things are already looking up.

Next, we have General Motors (GM) and Ford (F). Both companies could see shares move as the automakers release their U.S. sales data for December today. Analysts are predicting around 1.4 million new cars and trucks were sold last month in the U.S. That would make December the fourth best month of the year. G.M. is expected to see a rise of 0.8% in sales last month according to Edmunds.com. Ford is expected to see a rise of 5.9% in December sales. G.M. shares rose over 40% in 2013, while Ford shares rose close to 17%.

Now, chipmaker Micron Technology (MU), whose slide this morning came after the stock was downgraded by RBC Capital to sector perform from outperform. Micron was one of 2013's top stocks, up more than 228%.

Finally, Martha Stewart Living (MSO) saw its stock rise close to 9% by closing yesterday and could see more action today. The stock jump was in response to an announcement that Martha Stewart and Macy's (M) reached a settlement in a breach-of-contract suit. Macy's sued Martha Stewart and J.C. Penney (JCP) in 2012 after the two companies partnered up. Macy's claimed exclusive rights to many of the products Stewart agreed to design for J.C. Penney. Martha Stewart Living saw share soar over 62% in 2013, and is looking for an even better 2014 after this settlement.