Whatever way you look at it, ANZ is winning larger mortgage market shares for both home loans and rural mortgages. But challenger banks are also doing better

ANZ continues to gobble up home loan market share, winning more than a third of the growth in the final quarter of 2017.

Other banks who raised their market share in value terms include most of the challenger banks.

But all ANZ's main rivals leaked market share when it is measured on a value basis.

Mortgage market shares are relatively easy to assess from the RBNZ G1 data series, even if it does come with a four month delay.

As at December 2017 the data showed:

This table is a stock, showing book balances at the above dates.

Clearly the winners are ANZ and all the challenger banks.

Clearly the losers of market share are ASB, BNZ, Westpac and especially Kiwibank.

In fact, in this data Kiwibank's 2017 growth was eclipsed by TSB a bank with only a quarter the size in its mortgage book.

But the big deficiency in this data is understanding exactly where these quite substantial shifts are occuring.

To get some understanding of the regional shifts, we need to turn to the raw LINZ data where we can find the volumes of new mortgages registered.

Like the values, that involves market share shifts.

And it also allows us to inspect the shifts between types, like Residential, Lifestyle, and Rural mortgages registered.

Here is that data analysed for the same year, except by volume (number of mortgages) for residential transactions only:

This table is a Flow showing the transactions in the year for the period. Be careful interpreting the "Growth" percentages. These volumes are not the number of mortgages in Table 1; rather they are the number of new mortgages written in the referenced years.

This tells a different but still a very interesting story; there were -18% fewer residential mortgages registered by LINZ in 2017 than 2016, even as dollar values grew. That suggests fewer but much larger mortgages, rather than just more mortgages as suggested by the RBNZ valua data (up +6.7%).

ANZ's value gains are confirmed by this view. Even though they wrote fewer mortgages, their decline was less than all their other main rivals other than Westpac.

And the data in this view suggests that the challenger banks made 'real' relative gains, especially HSBC who adopted aggressive pricing during the period with a sub- 4% fixed rate offer.

ANZ and to some extent ASB made relative gains in rural mortgages versus their main rivals, although the really big movers in rural mortgage lending volumes were Rabobank, Heartland Bank, and perhaps somewhat surprisingly, TSB.

However, this following table takes a little longer view, comparing transactions in the December 2017 quarter with those of the same quarter three years ago when the rural (dairy) conversion was in still occurring.

This table is a Flow showing the transactions in the year for the period. Be careful interpreting the "Growth" percentages.

In a separate review, we will look at regional mortgage shares.