US stocks have opened modestly mixed after scoring their strongest week of the year, with investors keenly awaiting the new Federal Reserve chief Janet Yellen's first testimony to Congress.
Five minutes into trade, the Dow Jones Industrial Average was down 20.48 points (0.13 per cent) at 15,773.60.
The broad-based S&P 500 edged down 1.57 (0.09 per cent) to 1,795.45, while the tech-rich Nasdaq Composite Index rose 5.13 (0.12 per cent) to 4,130.99.
Yellen, who succeeded Ben Bernanke as Fed chair on February 1, presents the Fed's semi-annual view of the economy and monetary policy to lawmakers in two hearings this week, starting with a hearing on Tuesday of the House of Representatives Financial Services Committee.
"What Ms. Yellen says in her prepared remarks and in the Q&A portion of her testimony should set the tone for the week, not just for the stock market but for all capital markets," said Patrick O'Hare of Briefing. com.
The equities markets scored a net gain last week, shrugging off Friday's disappointing jobs report.
The Dow added 95.23 points (0.6 per cent), snapping a two-week losing streak with its largest weekly point and percentage gain since late December.
