Understanding Bankrate's rate averages

Bankrate's site displays two sets of rate averages that are produced from two surveys we conduct: one daily and the other weekly. They're both useful, but they're samples of different groups and they serve different purposes. In both sets of rate averages, Bankrate will compile averages on banking deposits, loans and mortgages.

You will see daily averages labeled "Bankrate.com Site Average"; these calculations are run after the close of the business day.

Included there are rates and/or yields we have collected on the previous day for a specific banking product. Bankrate.com site averages tend to be volatile. They help consumers see the movement of rates day to day. The institutions included in the "Bankrate.com Site Average" tables will be different from one day to the next, depending on which institutions' rates we gather on a particular day for presentation on the site.

The "Bankrate.com National Average," or "national survey of large lenders," is conducted weekly. The results of this survey are quoted in our weekly articles, the Interest Rate Roundup and our Mortgage Analysis. To conduct the National Average survey, Bankrate obtains rate information from the 10 largest banks and thrifts in 10 large U.S. markets. In the Bankrate.com national survey, our Market Analysis team  gathers rates and/or yields on banking deposits, loans and mortgages. We've conducted this survey in the same manner for more than 30 years, and because it's consistently done the way it is, it gives an accurate national apples-to-apples comparison.

The credit card index is based on a weekly survey of the 50 largest card issuers, ranked by total receivables, an industry standard measure.