I-Bonds are U.S. savings bonds whose yields are adjusted by the prevailing inflation rate

 You are allowed to purchase $10,000 of such bonds each year ($20,000 per married couple) and an additional $5,000 per year with your tax refund. 

 Zvi Bodie has done as much as anyone, if not more, to champion I-Bonds. Bodie, now retired, was for four decades a finance professor at Boston University.

MarketWatch 12 April 2022

https://www.marketwatch.com/story/the-silver-lining-of-surging-inflation-i-bond-yields-should-climb-above-9-11649784459