Repo market and related market issues/opinions.
There's some illuminating and entertaining stuff here too, different perspectives and informed ? opinion in both the article and readers comments/responses to it I think.
https://wolfstreet.com/2020/01/09/fed-drains-45-billion-from-repo-market-back-to-oct-level-t-bill-purchases-continue-balance-sheet-shrinks-by-most-since-qt/