Rates on 3-, 6-month T-bills decline in auction

The Treasury Department auctioned $21 billion in three-month bills at a discount rate of 4.965%, down from 5.035% last week. An additional $17 billion in six-month bills was auctioned at a discount rate of 4.855%, down from 4.950% last week.

The new discount rates understate the actual return to investors: 5.112% for three-month bills, with a $10,000 bill selling for $9,874.50, and 5.06% for a six-month bill selling for $9,754.55.

Separately, the Federal Reserve said the average yield for one-year Treasury bills, a popular index for making changes in adjustable rate mortgages, fell to 4.96% last week, down from 5.05% the previous week.