A month ago, the US issued $21 billion in 10 Year paper in what could only be dubbed as a "WTF Auction" - one in which every record was broken as demand for paper could seemingly not be satisfied. At 1 PM on July 11 the paper priced at 1.459%, a record-shattering 6 bps inside of the When Issued. What a difference a month makes. Not a month later and the just completed issuance of $24 billion in 10 Year paper could be classified as a collapse in demand, as the auction priced at 1.68% or a whopping 2.5 bps tail. Just as notably, after hitting an all time of 3.61 high last month, the Bid to Cover imploded to 2.49: the lowest broad demand indication since August of 2009. The internals were just as loopy: Direct take down imploded from a record 45.4% of total to just 5.2%, the lowest since November 2009, and with Indirects refusing to budge, the Primary Dealers were forced to take down 54.2%, or the most since October of 2011. And while the lack of interest was not surprising, especially in the aftermath of the just released Elliott Management letter (more on the later), the violent swings in demand for US paper at issue are starting to make quite a few desk traders very concerned. Because all it will take to crush the credibility of the bond market next is a few more such wild swings, and Geithner and Bernanke better hope that Knight can somehow be a DMM in TSY paper as well.