These indexes are the weekly or monthly average yields on U.S. Treasury securities adjusted to constant maturities*. Yields on Treasury securities at "constant maturity" are interpolated by the U.S. Treasury from the daily yield curve, which is based on the closing market bid yields on actively traded Treasury securities in the over-the-counter market.

* Constant Maturity Treasuries is a set of "theoretical" securities based on the most recently auctioned "real" securities: 1-, 3-, 6-month bills, 2-, 3-, 5-, 10-year notes, and also the 'off-the-runs' in the 7- to 20-year maturity range. The Constant Maturity Treasury rates are also known as "Treasury Yield Curve Rates".

The CMT indexes are volatile and move with the market. They reflect the state of the economy, and respond quickly to economic changes.

These indexes react more slowly than the CODI index, but more quickly than the COFI or the MTA.   More Indices: Libor , Prime Rate