'The long-term view is really quite dark. ': NEW YORK •  The U.S. yield curve reached it flattest level in over a decade on Monday afternoon as the White House said President Trump will nominate economist Richard Clarida as Federal Reserve Vice Chairman. The spread between five- and 30-year Treasury bonds fell to 34.6 basis points, the lowest in over 10 years. Expectations of further interest rate increases lifted the short end of the curve earlier in the day, led by the two-year government bond, which hit 2.394, its highest since September 2008.