U.S. stocks open mixed ahead of Yellen testimony

U.S. stocks opened narrowly mixed on Tuesday as investors await implications on the timing of an interest rate hike at Federal Reserve Chair Janet Yellen's speech to Congress.

Wall Street kept a watchful eye on Yellen's semi-annual testimony to Congress on Tuesday and Wednesday. Although many considered last week's Fed minutes as dovish, some analysts believed Yellen is likely to imply that a June rate hike is still on the table.

"So, it's really all about patience this morning, with a side order of whether the Fed cares about prolonged low inflation," said Chris Low, chief economist at FTN Financial, in a note.

To the relief of investors, the eurozone's finance ministers approved Greece's new bailout plan Tuesday.

Greece government tabled a "comprehensive" list of proposed reform measures for approval by the Eurogroup teleconference under the Feb. 20 deal for a four-month extension of the four year bailout to June.

S&P Dow Jones Indices Tuesday released the latest results for the S&P/Case-Shiller Home Price Indices, a leading measure of U.S. home prices. Data released for December 2014 showed a slight uptick in home prices across the country.

Compared to a 4.3 percent increase in November, the 20-City Composite gained 4.5 percent year-over-year, beating market expectations.

Shortly after the opening bell, the Dow Jones Industrial Average rose 22.48 points, or 0.12 percent, to 18,139.32. The S&P 500 edged down 0.50 points, or 0.02 percent, to 2,109.16. The Nasdaq Composite Index was down 8.08 points, or 0.16 percent, to 4,952.89.

U.S. stocks ended mixed Monday, with the Nasdaq Composite Index extending its gains into a nighth straight session, as investors shifted their focus from Greek debt concerns to Yellen's remarks in the next two days. Endi