The US Treasury is once again running on cash fumes, with total US Treasury cash down to $4.3 billion in the Treasury's Federal Reserve account. The reason: the US Treasury has now rolled $320 billion in total treasuries in the first ten days of the month, or over $11 trillion annualized. All those paying attention to interest paid on US debt are focusing on the wrong thing: the monthly scheduled amortization of principal are now by far a much greater threat to the US Treasury than a couple of percent increase in rates. The short-date sides of the curve is getting progressively larger, contrary to the UST's previously announced plan to extend the average duration of Treasury debt. After all, why issue 10 Year+ debt and take on auction and interest risk, when courtesy of everybody rushing away from the equity market, the interest in zero interest overnight maturities is virtually infinite... Unless, of course, you are Spain, where the interest is the opposite of infinite.