Rates on Short-Term T-Bills Mixed in Auction

The Treasury Department auctioned $18 billion in three-month bills at a discount rate of 4.150%, up from 4.070% last week. An additional $16 billion in six-month bills was auctioned at a discount rate of 4.250%, down from 4.265% last week.

The new discount rates understate the actual return to investors -- 4.252% for three-month bills, with a $10,000 bill selling for $9,895.10, and 4.404% for a six-month bill selling for $9,785.14.

Separately, the Federal Reserve said the average yield for one-year Treasury bills, the most popular index for making changes in adjustable-rate mortgages, rose to 4.37% last week from 4.36% the previous week.