Stocks To Watch For December 31, 2013

Some of the stocks that may grab investor focus today are:Berkshire Hathaway (NYSE: BRK-A) announced its plans to buy the flow improver business of Phillips 66 (NYSE: PSX) for about $1.4 billion of stock. Berkshire Hathaway shares fell 0.05% to close at $177,069.20 yesterday, while Phillips 66 shares gained 0.24% to $74.90 in after-hours trading.UniPixel (NASDAQ: UNXL) named its chairman, Bernard Marren, and director, Carl Yankowski, as interim co-president and co-CEO. UniPixel shares declined 12.81% to $10.28 in the after-hours trading session.KKR & Co LLP reported a 6.8% stake in Marvell Technology Group (NASDAQ: MRVL). Marvell shares surged 5.96% to $14.58 in after-hours trading.PTC (NASDAQ: PTC) reported that it has acquired ThingWorx for $112 million. It also projected Q1 revenue to be near the high-end of its earlier forecast of $310 million to $320 million. PTC shares gained 1.31% to $34.75 in the after-hours trading session.Acura Pharmaceuticals (NASDAQ: ACUR) entered into an agreement with Oxford Finance LLC for $10 million in debt financing. Acura Pharmaceuticals shares jumped 4.82% to $1.74 in after-hours trading.