LONDON—The U.S. dollar consolidated gains on Monday after hitting a 1–1/2 year high on Friday as the Treasury yield curve extended a three-week flattening streak following hawkish comments by a Federal Reserve official. With the Fed clearly signaling its intent to raise interest rates as early as March after its meeting last week, money markets and major Wall Street banks are now expecting as many as five rate hikes this year. But some investors expect policymakers are preparing the markets for a faster pace of rate increases this year to check inflationary pressures, especially after last week’s strong data. The Fed could supersize an interest rate increase to half a percentage point if inflation remains stubbornly high, Atlanta Fed President Raphael Bostic told the Financial Times in an interview. “Bostic is a non-FOMC voter so I would not get too carried away by his comments but you could say he …