Typically this index is the quickest to rise when prices of mortgage backed securities are rallying but its the slowest to decline compared to other economic indices.
With a traditional mortgage, if the LIBOR index or other index goes up, the mortgage rate rises with it, only much more frequently.
If you are considering an ARM that is indexed of the LIBOR index ask your mortgage broker for alternative indexes for your mortgage program. There are more stable indexes such as the COFI index and the COSI index.
One can always imagine a train when looking at the various indices. The LIBOR is the coal car (just behind the engines of the various government central banks), the COFI and COSI are situated in the caboose area. As the train goes up over hill and down the other side, the LIBOR is leading the way, the COFI and COSI are always in the back mimicking the LIBOR but with a several month lag time.
With the LIBOR ARMs borrowers are generally protected from wide fluctuations in interest rates by periodic and lifetime interest rate caps.
Compared to other Indexes, LIBOR is one of the least stable. It changes more often and by greater amounts
Most adjustable rate mortgages that are tied to the LIBOR index, are based on the six-month LIBOR rate.