To keep up with inflation, we invest in TreasuryDirect iBond which yields 7.12% this period. Although it limits only $10,000 a year for any SS, we can still buy each year. The best is to buy with many different amounts instead of one lump-sum $10k because we can’t sell the bond in parts. This bond is for 5 years without penalty and after 1 year we can redeem although we would lose some interests. Regardless, this iBond would beat any CDs currently offered at any bank.
This I bond is the same as 529 account for school, if we use the money for school, we don’t have to pay tax on the interests. This iBond has no state tax on interests, just Federal. This bond is compounded semi-anually therefore we would double our investment in 15 years.