Here is an interesting article. It talks about how the fed reduced the balance sheet after Oct 25th which is the date reported in Gregs most recent report that he linked to.

http://www.businessinsider.com/fed-balance-sheet-normalization-is-happening-2017-12

"The Fed doesn't actually sell Treasury securities outright. Instead, it allows some of them, when they mature, to "roll off" the balance sheet without replacement. When the securities mature, the Treasury Department pays the holder the face value. But the Fed, instead of reinvesting the money in new Treasuries, destroys the money - the opposite process of QE, when the Fed created the money to buy securities.

This happens only on dates when Treasuries that the Fed holds mature, usually once or twice a month.

In October, the big day was October 31, when $8.5 billion of Treasuries on the Fed's books matured. The Fed reinvested $2.5 billion and let $6 billion "roll off." Hence, the amount of Treasuries fell by about $6 billion from an all-time record $2,465.7 billion on October 25 to $2,459.8 billion on November 1."