Interest rates on short-term Treasury securities were mixed in Monday's auction.
The Treasury Department sold $9.5 billion in three-month bills at a discount rate of 5.960 percent, up from 5.945 percent last week. An additional $8.5 billion was sold in six-month bills at a rate of 5.935 percent, down from 5.955 percent.
The new discount rates understate the actual return to investors -- 6.137 percent for three-month bills with a $10,000 bill selling for $9,849.30, and 6.203 percent for a six-month bill selling for $9,700.
Separately, the Federal Reserve said that the average yield for one-year Treasury bills, the most popular index for making changes in adjustable rate mortgages, fell to 6.14 percent, from 6.20 percent.