Cite for that? No one with any expertise has predicted a >7% inflation level that I'm aware of. This sounds like something you got from talk radio.
(Edit: two replies have taken this out of context. Savings bonds have a minimum term of five years (well, without penalty). For them to have a negative yield, we need to see aggregate inflation >7.12% over the next five years. That's nuts, sorry. No one is predicting that.)
(Edit: two replies have taken this out of context. Savings bonds have a minimum term of five years (well, without penalty). For them to have a negative yield, we need to see aggregate inflation >7.12% over the next five years. That's nuts, sorry. No one is predicting that.)