The Fed may have officially tapered QE at the end of 2014 but that doesn’t mean it is done buying Treasuries: since the Fed never ended rolling over maturing paper, it means that it will remain indefinitely active in the open market. And while there were no sizable maturities from the Fed’s various QEs to date (only $474 million in 2014 and $3.5 billion in 2015) that will change dramatically this year, when Brian Sack’s team will have to purchase about $216 billion to replace matured TSYs.