John owns a bond portfolio worth $2 million with duration of 10.

To hedge a bond portfolio against small parallel shifts in the term structure, you need to take a position in an instrument with an equal and opposite duration. John has a bond portfolio worth $2 million with a duration of 10. To hedge this, he should take a short position in bonds worth $20 million with a duration of 1. This is because the product of the value and duration of the hedge position should equal the product of the value and duration of the original portfolio (2 million * 10 = 20 million * 1).