Kiwibank matches most of the market

Notably, despite wholesale markets having priced in a cut of about 30 basis points in the OCR by September, not a single bank has cut its floating rate.

It is also notable none of the banks are passing on into their standard rates the full extent of the drop in wholesale interest rates recently. For example, since April 12, three-year swap rates have fallen about 100 basis points and five-year swap rates are down more than 70 points.

Kiwibank is keeping its 4.99% one-year fixed rate for those with equity of at least 30% but reiterated it's for "a limited time."

"Kiwibank normally operates short-term specials for no more than three weeks but is keeping the 4.99% offer open because of the phenomenal success of the promotion," it says.