IUL policies allow you to grow your cash value by putting a portion toward an equity index account like the S&P 500 or NASDAQ. Rather than only relying on non-equity earned rates, an equity index account grows based on the index of an entire market or market sector. The interest rate will still be variable, like with other universal life policies. And as with all universal life policies, your IUL cash value will have a minimum interest rate that it will always earn, regardless of market performance. Your IUL may also have an interest rate cap.