So, if a bond was issued when interest rates were lower, they might have a 4% coupon when the prevailing rate is 6%.

所以，如果一只债券在利率很低的时候发行，在汇率为6%的的时候，它们可能有一个4%的票息。

耶鲁公开课 - 金融市场课程节选

Well it could go twenty basis points lower but interest rates can never be negative.

呃，它可以再跌二十个基本点,但是利率永远不能是负值。

耶鲁公开课 - 金融市场课程节选

Buying them tends to push up the price; that tends to influence the yield down so it encourages a lower level of interest rate.

买进它们，导致价格上升；,导致参数降低,所以它鼓励一个低的利率水平。

耶鲁公开课 - 金融市场课程节选