I Bonds question

[EarlyInJourney]

I have 20K in I Bonds, 10K purchased Dec. 2021, 10K purchased April 2022.

I would like to continue at the 20K level.  Since the bonds I bought have a 0% fixed rate, would it make sense to sell 10K in early January 2023, and later in the month buy 10K of new bonds to take advantage of the .4% fixed rate being offered through April '23?  Higher floor and all that?  Or should I hedge my bet a bit and buy 5K in January, just in case the fixed rate will be higher come May 2023?  (seems hard to predict this...) 

Thanks!

[seattlecyclone]

You lose the last three months of interest when you sell within five years of purchase. With the higher fixed rate you may come out ahead eventually on the trade, but I'll leave that math to you.

[blue_green_sparks]

This handy dandy tool can save you some calculations and does look ahead as far as it can.
http://eyebonds.info/ibonds/home10000.html

[EarlyInJourney]

Thanks, that really is a handy dandy tool!  But too much uncertainty re: future inflation/rates to really do the math...  I think I'm going to scrimp and save and just try to buy some new bonds without selling the old ones... It's hard (but not impossible) to imagine inflation going down so sharply that rates also take a dive and make I bonds a bad option the next 12-18 months. 

FWIW, I bonds are serving as the super safe part of my asset allocation; my 457b/401k contributions are almost all going to a total market fund.