The Monthly Treasury Average has not been lower in any of the last five months, and underlying fundamentals are placing upward pressure on the index.
Last month, the daily average for the one-year Treasury note was 0.18 percent, the same as the prior month.
A 12-month average of the daily one-year average — also known as the MTA — worked out to 0.16000 percent in September, rising from 0.15333 percent in August when the index was up less than a basis point from July.
There has been no decline in MTAÂ since April, when it stood at 0.14667 percent.
But the index was lower than in September 2011, when it stood at 0.21750 percent.
MTAÂ is used to determine interest rate changes on some adjustable-rate mortgages.
Other ARM indices include the yield on the one-year Treasury note, which inched up to 0.17 percent as of the end of September from 0.16 percent at the end of August, and the six-month London Interbank Offered Rate, which declined to 0.65 percent from 0.71 percent.
ARM share was a meager 2.6 percent in the U.S. Mortgage Market Index from Mortech Inc. and Mortgage Daily for the week ended Sept. 28 as record-low fixed rates lure new prospects away from ARMs.