Investing.com - Attention shifts back to U.S. tax reform ahead of a Senate vote that could come as early as Thursday. On Tuesday the Senate Banking Committee will hold a confirmation hearing for Fed Governor Jerome Powell, selected by President Donald Trump as the next Fed chair.Outgoing Fed Chair Janet Yellen is to testify on the U.S. economic outlook before the Joint Economic Committee of Congress in Washington on Wednesday.Investors will also receive an update on the strength of the U.S. economy on Wednesday with revised Q3 GDP figures.OPEC and its partners are to meet on Thursday, a year after agreeing to oil output cuts for an initial period of six months.