Once again the Fed decided on a 9-1 vote to leave the key interest rate unchanged. The downplayed global weakness, which was one of the main reasons for not hiking rates in December. They cited a slowdown in the labor market and that measures of inflation are still below the target rate they have previously set for a hike while the economic growth is seen as moderate. The statement did leave the door open for a rate hike in December which caused mortgage backed securities to immediately nosedive.
Once again they offer very little clarity on their direction so you can expect markets to fluctuate in the short term.