美国财政部在长期债务回购中购买的债券数量少于预期，即使在最近扩大了该计划的范围之后也是如此，这引发了投资者对其目标以及是否成功的争论。
The US Treasury is purchasing fewer bonds than expected in its buybacks of longer-dated debt, even after recently expanding the program's scope, stoking debate among investors over its aims and whether it is succeeding.