Rates on US Treasury bills rise to highest in 8 years

Interest rates on short-term Treasury bills rose in Monday's auction to their highest levels in eight years.

The Treasury Department auctioned $42 billion in three-month bills at a discount rate of 0.515 percent, up from 0.420 percent last week. Another $36 billion in six-month bills was auctioned at a discount rate of 0.625 percent, up from 0.535 percent last week.

The three-month rate was the highest since three-month bills averaged 0.530 percent on Nov. 3, 2008. The six-month rate was the highest since those bills averaged 0.840 percent on Nov. 17, 2008.

The discount rates reflect that the bills sell for less than face value. For a $10,000 bill, the three-month price was $9,986.98, while a six-month bill sold for $9,968.40. That would equal an annualized rate of 0.523 percent for the three-month bills and 0.636 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, ended last week at 0.73 percent, up from 0.63 percent at the start of the week on Nov. 7.