Tuesday's rally in U.S. government debt pushed the yield on the long-dated Treasury bond to its lowest level in more than a week, just one day before the Federal Reserve's next policy announcement.

U.S. government debt rallied on Tuesday, pushing yields lower for the day, as risk-off sentiment took hold in the stock market and the Federal Reserve’s two-day policy meeting got underway.

William Pulte, the new director of the Federal Housing Finance Agency, is consolidating control over Fannie Mae and Freddie ...