There have long been calls for the Commerce Commission to look into competition in the banking sector, and it's now happening.
The government announced yesterday the watchdog would run a market study to ensure the market is working well for New Zealanders.
The banks say there is competition aplenty, and Finance Minister Grant Robertson suggests if that's the case, they have nothing to worry about.
Sam Stubbs, who runs Kiwisaver fund Simplicity, spoke to Corin Dann.