Inland Revenue has provided an update on its guidance of how it treats what it calls “cryptoassets” at: https://www.ird.govt.nz/cryptoassets
A link to the IRD media release can be found at: https://media.ird.govt.nz/articles/new-inland-revenue-guidance-on-cryptoassets/
The high level summary is:
There are no special tax rules for cryptoassets in New Zealand. The guidance clarifies how ordinary income tax rules apply to cryptoassets to help people understand their tax obligations.
Essentially, cryptoassets are treated as a form of property for tax purposes. What people make from selling, trading or exchanging crypto-assets is taxable