It was the first time in nearly a year that the 11th District Cost of Funds Index increased.
Coming in at 1.360 percent for May, COFIÂ nudged up one-tenth of one basis point from the previous month, the Federal Home Loan Bank of San Francisco reported.
The last time the index rose was in June 2010, when it stood at 1.797 percent.
In May 2010, COFIÂ was 1.791 percent.
The FHLB determines the index based on interest expenses at FHLB members based in Arizona, California and Nevada. Average total funds used in May’s calculation were $35.7 billion, the same as a month earlier.
COFI is the index for many adjustable-rate mortgages such as those originated by World Savings that were inherited by Wells Fargo & Co. through its acquisition of Wachovia Corp.
But a more widely used ARM index, the yield on the one-year Treasury note, fell to 0.18 percent in May from 0.22 percent a month earlier, according to data from the Department of the Treasury. The one-year yield was 0.19 percent at the end of June.
ARM share of new loan pricing inquiries was down to 10.05 percent for the week ended June 24 from 10.22 percent the prior week, according to the U.S. Mortgage Market Index report from Mortech Inc. and MortgageDaily.com.