<prompt> Human: Hi PersonalFinance,My grandparents, who are well into retirement Grandpa is in his 90s, Grandma her 80s have about 60,000 in extra cash that they would like to invest with the hopes of it earning some returns of them. My understanding is that this money is truly extra money, and that while they dont want to take any substantial risks with it given their age, theyd like to invest it in a way that can earn them more than what a savings account or CD would.My thinking is that their best option is to invest the money in some low-expense Vanguard Bond funds, but given that theyve asked me for advice and its not a small chunk of change, I had hoped to hear your thoughts as well, just to ensure Im not way off base.Thanks for your help!  <response>: Keep in mind that investing in bond funds is not the same thing as investing in bonds. The value of that bond fund will be highly sensitive to changes in the interest rate, and interest rates only have one way to go: up. When interest rates move up, the value of that bond fund will go down. CNBC has a good introductory article about this. Honestly, unless they would consider doing something like plopping the money into a 529 for the grandkids essentially gifting it where it could be invested in stocks because of a longer investment horizon, I dont see much of an advantage in doing anything other than CDs. Consider: a 5-year CD yields 1.75, while a 5-year AAA municipal bond has a tax-equivalent yield of about 2. Fact is, cash and CDs are not that bad a place to be right now for folks like your grandparents. 