The new Financial Markets Authority officially opened for business on Sunday.
It takes over the functions of the Securities Commission and the Government Actuary which are being disestablished.
Commerce Minister Simon Power announced the authority's formation about a year ago.
He says it will lift the bar in terms of market behaviour.
Mr Power says the authority will have the tools it needs to help restore Mum and Dad investor confidence in financial markets.
He says it will have new powers its predecessors did not.
This includes being able to exercise an investor's right to take civil action against a financial market participant, when it's considered to be in the public interest to do so.
The Financial Markets Authority will also have the ability to undertake real-time surveillance of market activity.
