For the most popular three-year term, there are now some fixed rate home loans with interest rates just under 4 per cent. That's very cheap debt.

It's near impossible to say if these rates will fall even further – that's the risk with fixing. But it's worth acknowledging the potential savings, as some fixed rates are are now significantly lower than the average discounted average variable rate of about 4.8 per cent.

Most home loans in Australia have variable interest rates, which tend to move when the Reserve Bank changes the official rate. Fixed interest rates, however, move in a different way.

Figures from Canstar show that more than 30 lenders, including regional mortgage providers such as Suncorp and ME Bank, have reduced their three-year fixed rates since the beginning of March – a period when the RBA has not changed official rates.

Many of these cuts were made on top of cuts in February, and it's meant the average three-year fixed rate has fallen by more than the 0.25 percentage point reduction in variable rate home loans so far this year.

ME Bank last week cut its three-year fixed rate to 3.99 per cent, a rate also being offered by Newcastle Permanent Building Society and non-bank lender iMortgage at the time of writing.

Lenders are cutting fixed rate loans because it has become easier for banks to lock in this funding and pass the saving on to borrowers.

The interest rate on a fixed rate loan reflects financial market expectations about where official rates will go in the future. And financial markets have recently placed growing bets on at least one, maybe two, further interest rate cuts from RBA governor Glenn Stevens.

ME Bank's general manager markets, John Caelli​, says this has meant a decline in a key benchmark rate that broadly represents the cost to banks of locking in funding.

"The market's very much of the view that the Reserve Bank will continue to cut rates," he says.

Despite these low fixed rates, however, brokers say relatively few people are taking up the offer. Borrowers are typically reluctant to lock in a fixed rate when there's a perception that variable rates will fall even further. It seems like you'd be deliberately depriving yourself a future rate cut, right?

Well, not necessarily. The difficulty is that fixed rates tend to bottom out before official rates do, because they reflect expectations about the future.

In other words, there is no guarantee they will fall any lower than they are today, (although, of course, that is possible). Whatever happens, fixed rates are undeniably very low at the moment, and this gives borrowers the option to lock in cheap financing for some of their loan.