The Dow Jones Industrial Average (^DJI 0.56%) had fallen 39 points as of 11:30 a.m. EDT. Microsoft (MSFT -1.27%) was one of few Dow Jones components in the green, while fellow tech stocks MICROS Systems (NASDAQ: MCRS) and PLX Technology (NASDAQ: PLXT) also posted notable moves to the upside.

Dow slumps despite economic data
The sell-off in the Dow Jones came despite some better-than-expected economic data. 

According to the National Association of Realtors, existing-home sales rose 4.9% in May to a seasonally adjusted annual rate of 4.89 million, handily beating the 2.2% increase that economists had expected. The strength of the U.S. housing market is widely seen as a measure of economic strength. Increasing home sales suggest the labor market is improving -- a good sign for the U.S. economy and, by extension, the stock market.

Source: Wikimedia Commons.

Microsoft defies Dow sell-off
Microsoft shares rose 0.2% early in the session. But there wasn't much news to explain Microsoft's rise. 

Late last week, Microsoft's Surface Pro 3 went on sale to the public. The third version of the Surface tablet is, in many ways, the perfection of Microsoft's original vision -- one device that doubles as both a laptop and a tablet. Reviews of the device have been mixed. While most agree that the Surface Pro 3 is the best Surface system yet released, there is still some skepticism that a tablet can truly replace a laptop.

Avago acquires PLX Tech
PLX Tech shares rose more than 9% early on Monday after Avago announced that it would acquire the company for about $300 million in cash. The deal values PLX Tech shares at about $6.50.

PLX Tech develops PCI Express technology, an interface commonly used in traditional PCs. Avago likewise specializes in tech components, and the combined company will have a larger portfolio of products to offer in the space.

Oracle buys MICROS
MICROS shares rose more than 3.4% early on Monday after Oracle announced that it would acquire the company for $5.3 billion in cash. MICROS develops software used in restaurants and other hospitality businesses, powering the terminals that servers use to input customer orders. Oracle's offer values MICROS shares at $68.

Cantor Fitzgerald reacted positively to the news, saying the deal opened up a healthy opportunity for Oracle in the food and beverage space. Cantor maintained its buy rating on Oracle with a $50 price target.