Rates flat to up slightly at weekly US Treasury bill auction

Interest rates on short-term Treasury bills were flat to slightly higher in Monday's auction.

The Treasury Department auctioned $42 billion in three-month bills at a discount rate of 0.340 percent, unchanged from last week. Another $36 billion in six-month bills was auctioned at a discount rate of 0.475 percent, up slightly from 0.470 percent last week.

The six-month rate was the highest since those bills averaged 0.495 percent on Oct. 11.

The discount rates reflect that the bills sell for less than face value. For a $10,000 bill, the three-month price was $9,991.41, while a six-month bill sold for $9,976.96. That would equal an annualized rate of 0.345 percent for the three-month bills and 0.483 percent for the six-month bills.

Separately, the Federal Reserve said Monday that the average yield for one-year Treasury bills, a popular index for making changes in adjustable-rate mortgages, edged up to 0.66 percent last Friday after starting the week at 0.65 percent on Monday, Oct. 17.