Modified duration is actually negative, but in practice the minus sign is often dropped.

Question

Quizplus · Accepted Answer

Modified duration measures the percentage change in the price of a bond for a 1% change in yield. Theoretically, bond prices and yields move in opposite directions, which would make the modified duration negative. However, in practice, the negative sign is ignored because the focus is on the magnitude of sensitivity rather than the direction of the relationship.

Modified Duration Is Actually Negative, but in Practice the Minus