On September 9 the Treasury runs the first operation under a bond buyback program it doubled in size this August, one that two senior officials say could draw on a $950 billion cash reserve, though they would not say how much, if any. The same week, two independent pieces of research price the thing that is actually running short. It is not demand for Treasurys. It is the capacity to keep them safe. The Twist, and what it buys Two senior Treasury officials, speaking to CNBC,