当然，要了解I-bond，功课还要自己做。比如: 至少持有一年才可以兑现；持有不到5年就兑现，要损失3个月的利息。每六个月利息会调整一次
The composite rate for I bonds issued from November 2021 through April 2022 is 7.12 percent. This rate applies for the first six months you own the bond.
An I bond earns interest monthly from the first day of the month in the issue date. The interest accrues (is added to the bond) until the bond reaches 30 years or you cash the bond, whichever comes first.
The interest on I bonds is a combination of
You know the fixed rate of interest that you will get for your bond when you buy the bond. The fixed rate never changes.
Treasury announces the fixed rate for I bonds every six months (on the first business day in May and on the first business day in November). The fixed rate then applies to all I bonds issued during the next six months.
The fixed rate is an annual rate.
The inflation rate can, and usually does, change every six months.
We set the inflation rate every six months (on the first business day of May and on the first business day of November), based on changes in the non-seasonally adjusted Consumer Price Index for all Urban Consumers (CPI-U) for all items, including food and energy.
However, the change is applied to your bond every six months from the bond's issue date. (The dates for these changes might not be May 1 and November 1.) When does my bond change rates?
To get the actual rate of interest (sometimes referred to as the composite or earnings rate) we combine the fixed rate and the inflation rate, using the equation in the example below.