As expected, the Monthly Treasury Average hit a new low last month, and odds are that another new low is ahead.
MTA fell to the lowest level on record in November based on Federal Reserve data dating back to 1953: 0.13333 percent.
The index, which is used to determine rate and payment changes on some adjustable-rate mortgages, declined from a record-low 0.13833 percent in October.
A year earlier, MTA stood at 0.17167 percent.
The index is calculated based on the daily average of the one-year Treasury yield for the last 12 months. The daily average in November was 0.12 percent.
Unless the daily average in December jumps to 0.16 percent, a new record low will be established this month.
A much more popular ARM index is the yield on the one-year Treasury itself, which closed at 0.13 percent in November, rising from 0.10 percent at the end of October.
On Monday, the one-year Treasury yield was 0.13 percent.