I currently have about six different TBILLS and two bonds. I started purchasing when they were 4.75%. Most recent have been as high as 5.35%.
https://treasurydirect.gov/auctions/announcements-data-results/
Way to go. I started buying T-Bills about 18 months ago when the banks were paying .5% and the T-Bills were at 1.8%. Been riding them up ever since. They are my largest holding except for real estate.