When using a portfolio rate, what would cause the portfolio interest rate on a Universal Life to perform better than the market in an extended declining interest rate market and yet would perform worse than the market in an extended increasing interest rate environment? Note: A Universal life (UL) insurance traditionally uses what is referred to as a portfolio rate when paying interest to a policyholder. When the market interest rate fall, portfolio rate follows behind with a slower slope. When the market interest rates rise, portfolio rate rises too but much slower. What causes this?