5 Things You Should Know Before the Stock Market Opens

NEW YORK ( TheStreet) -- U.S. stock futures were trading slightly lower Tuesday ahead of the release of the minutes from the Federal Reserve's policy meeting last month.

European shares were lower, while Asian stocks gained on the back of Monday's gains in the U.S.

Investors Tuesday will look to the Fed minutes for the central bank's thinking on the possibility of further quantitative easing.

The economic calendar Tuesday includes factory orders for February at 10 a.m. EDT. The consensus estimate, according to Briefing.com, is for an increase of 1.4% vs. a decline of 1% in January.

The European Union opened two investigations into whether Motorola Mobility ( MMI), which is being acquired by Google ( GOOG), is unfairly restricting competitors from accessing essential patents, The Associated Press reported.

The formal investigations were announced Tuesday after Apple ( AAPL) and Microsoft ( MSFT) complained to the European Commission that Motorola Mobility was using injunctions against their key products including the iPhone, iPad or Xbox as a way of gaining an edge in the market for similar products, the AP said.

Groupon's ( GRON) revision of its first set of financial results as a public company is being examined by the Securities and Exchange Commission, a report said.

The SEC's probe into the online deal company is at a preliminary stage and the SEC hasn't yet decided whether to launch a formal investigation into the matter, a person familiar with the situation told The Wall Street Journal.

Groupon revised its reported fourth-quarter results lower and said its independent auditor determined it has a "material weakness" in its internal controls.

Will Mitt Romney lock up the GOP nomination for president if he wins Tuesday's primaries in Wisconsin, Maryland and Washington D.C.?

Romney is leading in the polls in all three races, and a sweep on Tuesday could put an end to Rick Santorum's bid to challenge Barack Obama on Nov. 6, according to many pundits.

The Kentucky Wildcats (38-2) beat the Kansas Jayhawks 67-59 Monday night for the team's first NCAA championship since 1998.

-- Written by Joseph Woelfel

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