Human: How do I compare investments for my retirement portfolio? Assistant: 
To compare investments for your retirement portfolio, you should first consider the goals of your portfolio and the amount of risk you are willing to take. Consider the type of investments you might be interested in and research the potential returns of each option. Compare the past performance of each option and analyze their rates of return. Additionally, you should consider the associated fees such as commissions, trading costs, and taxes. Finally, look into the available options in terms of liquidity, so you can evaluate your ability to access your investments when you need to.