The Dow Jones Industrial Average (^DJI -0.11%) had tumbled more than 86 points as of 11:30 a.m. EDT. Microsoft (MSFT 0.37%) fell harder than its index, while shares of Twitter (TWTR) plunged. Apple (AAPL 1.27%), meanwhile, was just under breakeven after fading from a modest rally.

U.S. trade deficit contracts
The U.S. trade deficit contracted from February to March, according to data released by the Bureau of Economic Analysis. The total U.S. trade gap was $40.4 billion -- economists had been looking for a deficit of about $40 billion. 

Overall, the U.S. trade balance is not considered a major economic indicator, and is unlikely to be behind the Dow Jones' decline. Still, the data suggests a slightly weaker than expected domestic economy, with the U.S. exporting fewer goods than otherwise anticipated.

Source: Lachian Hardy via Wikimedia Commons.

Microsoft could launch another tablet
Microsoft was down nearly 1% in morning trading. The tech giant has scheduled a media event on May 20, during which it is expected to unveil a third Surface tablet. This new version of the Surface is widely believed to be smaller than its predecessors, perhaps sporting an 8-inch screen.

If priced aggressively, the smaller Surface could prove more popular than the existing Surface 2 and Surface Pro 2, which have posted relatively disappointing sales. Last quarter, Microsoft reported Surface revenue of $500 million -- assuming an average selling price of $700, Microsoft may have sold fewer than 1 million Surface tablets last quarter (the company doesn't disclose unit sales data). In comparison, Apple sold more than 16 million iPads during its last quarter.

Apple said to prepare huge iPhone upgrade initiative
Apple is planning a major push that could help drive sales of the iPhone, according to 9to5Mac. Apple intends to email iPhone owners with older models, encouraging them to upgrade.

Given that millions of iPhone owners still sport older devices, including the iPhone 4 and 4S, Apple's sales push could help drive millions of additional sales this quarter. It's unknown if Apple will provide some sort of monetary discount, but it seems likely, given that the company's retail stores are said to be preparing for an iPhone launch-like event.

Twitter plunges on lockup
Twitter shares fell more than 11% in early trading. The move was likely prompted by a major lockup expiration -- insiders, contractually obligated to hold onto their shares, were now able to sell their stock into the public market.

Many of them may have been doing so. Now trading below $35, Twitter's stock is at an all-time low. Admittedly, the stock has been exceptionally volatile since the company's IPO last fall, but since the end of December Twitter shares are now down more than 50%.