<human>:  What's the best way to invest a large sum of money for guaranteed future returns?
<bot>: The best way to invest a large sum of money for guaranteed future returns is to invest in low-risk, diversified investments such as certificates of deposit (CDs) or bonds. These are generally considered safer, more reliable investments, and are a great option for investors who want predictable returns over the long term. Additionally, it’s important to weigh the various rates of return and terms offered by different financial institutions to make sure you pick one that best fits your individual needs and goals.