I Bonds, also known as Series I Bonds, are non-marketable savings bonds issued by the U.S. Department of Treasury primarily for individuals to purchase and invest in.
The fixed-rate and the inflation rate are added together to give you the composite rate. The current fixed rate is 0% which will remain constant over the life of the I bond.
No risk
I Bonds have relatively low default risk, and I Bonds are also backed by the U.S. government that is considered highly unlikely to default on I Bond holders.