The Cost of Funds Index is a weighted average fund. There are two types of funds for each side of the country. In the eastern states this type of fund is commonly referred to as the 1-Year Treasury Security. In the western states the Cost of Funds Index is typically prevalent with the 11th District Cost of Funds.
The Federal Home Loan Bank of San Francisco continually publishes the monthly weighted average for the 11th District Fund. Over half of the savings and loan institutions in California are tied to this index. It is comprised of different institutions in not only California, but Arizona and Nevada as well.