Tax in the US
No. Tax only applies to dividends.

Tax in NZ - Individuals with $50,000 NZD or less invested overseas
Maybe. If your overseas investments (excluding any investments held in a PIE) total less than $50,000 NZD for the whole tax year, you shouldn't need to pay tax on any gains as long as you didn't buy the shares for the purpose of selling them, aren't in the business of buying such investments, aren't a dealer in such investments and didn't buy them as part of a profit-making scheme. We recommend you chat to your professional tax advisor to understand your obligations.

Note: If you’re a tax resident outside New Zealand you’ll need to consider the tax rules for every other country, including double tax agreements. As always, we recommend seeking professional tax advice.

Tax in NZ - Trusts or individuals with $50,000 NZD or more invested overseas
Yes. If your overseas investments (excluding any investments held in a PIE) as an individual total over $50,000 NZD, your overseas investments will generally be taxed under the Foreign Investment Fund (FIF) rules and you will not be taxed separately on any gains you make on the sale of your shares. We recommend you chat to your professional tax advisor before investing in Hatch.

For more information, here's a tax blog with more detail. 

Note: Your tax obligations will depend on your situation, so we recommend that you seek professional tax advice. These obligations may change over time, it’s your responsibility to keep up to date with changes.

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