You manage a pension fund that will provide retired workers with lifetime annuities. You determine that the payouts of the fund are (approximately) level perpetuities of $1 million per year. The interest rate is 10%. You plan to fully fund the obligation using 5-year maturity and 20-year maturity zero-coupon bonds.

(c) If interest rate increases to 11% right after you constructing your portfolio, what actions are needed to rebalance your portfolio?