A 247wallst.com personal finance article by Gerelyn Terzo works through the case of a hypothetical 58-year-old federal employee with $100,000 in the Thrift Savings Plan's F Fund as 10-year Treasury yields near 5%, where a one-point rise could cut roughly $5,730 from his balance. 24/7 Wall St. suggests the G Fund, which the government guarantees against principal loss, may suit money he expects to spend soon, though it cautions that safety carries a cost in potential returns, and it advises counting withdrawals needed in the first five years of retirement.