Subject: Re: SOLD : $423.25
"Then I bought May 30 T-bills at 98.655"

Is that the net price you got? Because I bought some May 30 T-bills today at auction and they were 96.6717 which results in a stated rate of 5.255% and an investment (annualized) rate of 5.400%.

These were the reported results of today's auction -

Term: 13-Week
High Rate: 5.255%
Investment Rate*: 5.400%
Price: $98.671653
Allotted at High: 71.62%
Total Tendered: $236,704,744,300
Total Accepted: $84,497,713,900
Issue Date: 02/29/2024
Maturity Date: 05/30/2024
CUSIP: 912797HS9

*Equivalent coupon-issue yield