The COFI index history (or the history of the 11th District Cost of Funds Index) shows that COFI is the most sluggish of all ARM indexes. Therefore, some ARM loans tied to the COFI index are the best consumer products on the market, as borrowers enjoy a little greater stability and better rates than other ARM loans.

Recommendation: Look for a COFI-based Option ARM.

The COFI index is maintained by savings institutions in California, Arizona and Nevada. COFI index history graphs show that it is a much slower changing ARM index and is great when market rates are rising, but not so great when market rates are going down.

The COFI index history shows that COFI tends to move opposite market trends at certain moments. If anyone needs historical COFI values, some websites keep a database with COFI values for almost 30 years.