The personal finance website says that fixed rate mortgages now account for 69%, compared to 51% this time last year.
It says that although the two-year swap rate has gone down by 2.61 percentage points since October 1, the average two-year fixed rate mortgage has only dropped by 0.71 percentage points.
The margin between costs to lenders on the swap rate market and mortgage rates has gone from 1.12 percentage points last year to 2.92 percentage points currently.
Michelle Slade, analyst at Moneyfacts.co.uk, says: “By not reintroducing cheaper tracker mortgages to the market, the lenders are leaving borrowers with little option but to go on to more expensive fixed rate mortgages.
“It is evident that lenders are continuing to increase their margins, despite a fall in the cost of funding.”
She adds: “Borrowers expect to pay a slightly increased price to fix their mortgage repayments compared to tracker deals. But today the gap between the average two-year fixed and tracker mortgage stands at 1.16%, compared to just 0.14% this time last year.”