Portfolio construction for NZ investors: what to actually put in it

The past four weeks have covered the structural context for NZ investors: why the rules are different here, which platforms suit which investor profiles, and how to avoid the most common and costly mistakes around FIF and PIR. This week the question is simpler and harder at the same time. You have sorted your platform. Now what do you actually put in it?

Portfolio construction is where most NZ investors get the least useful guidance. The US-centric content that dominates personal finance writing assumes a universe of accounts and instruments that does not exist here. The NZ-specific content tends to be either overly simplistic or product-focused in ways that are not always in your interest. What follows is how I think about it, built around the actual constraints and advantages of investing from New Zealand.

Start with the home bias problem

Home bias is the tendency for investors to overweight domestic assets relative to what a purely market-cap-weighted global portfolio would suggest. It is a well-documented phenomenon in every country, driven by familiarity, currency comfort, and the convenience of locally listed assets.

For New Zealand investors, home bias is a particularly serious problem. The NZX represents roughly 0.1% of global equity market capitalisation. A fully home-biased NZ investor is concentrating their entire portfolio in one of the smallest, most sector-concentrated equity markets in the developed world. The NZX is dominated by utilities, property, and a handful of large consumer businesses. It has almost no technology exposure, minimal financial services depth, and very limited industrials. Holding only NZ equities is not a conservative strategy. It is a concentrated bet on a narrow slice of the global economy.

That said, there are real reasons to hold some NZ equities. Currency alignment is one: NZ assets are denominated in NZD, which removes the currency risk that comes with international holdings. Dividend imputation credits are another: NZ companies can pass on tax credits to shareholders in a way that meaningfully improves after-tax returns for NZ resident investors. And there is a genuine long-term case for some home market exposure as part of a diversified portfolio.

The question is how much. The answer is almost certainly less than most NZ investors currently hold.

Advertisement · 728 × 90

The case for global diversification

A market-cap-weighted global equity portfolio today is roughly 65% US equities, 15% other developed markets, and the remainder split between emerging markets and smaller developed economies. New Zealand at 0.1% is a rounding error.

That does not mean you should hold 65% of your portfolio in US equities. It does mean that a portfolio without meaningful international exposure is structurally underweight the majority of the world's productive capital. The companies that have driven the most significant wealth creation over the past two decades — in technology, healthcare, and consumer sectors — are predominantly listed in the US and to a lesser extent Europe and Asia. None of them are on the NZX.

For most NZ investors, the practical implication is straightforward: the core of a long-term portfolio should be globally diversified, with NZ equities as a deliberate allocation rather than a default.

How much NZ equities?

There is no single right answer, but the academic literature on home bias and portfolio optimisation generally suggests that a moderate home bias — holding somewhat more than your market-cap weight in domestic assets — can be justified on the grounds of currency matching and reduced transaction costs. For NZ investors, that might suggest a NZ equity allocation of 10% to 20% of a total equity portfolio, rather than the 0.1% that pure market-cap weighting would imply.

What it does not suggest is 50% or more in NZ equities, which is closer to what many NZ KiwiSaver funds and retail investors actually hold. The diversification benefit of global exposure is too significant to give up that much of it.

The Australian question

Australian equities sit in an interesting position for NZ investors. The ASX is a larger and more diversified market than the NZX, with meaningful financial services, resources and materials exposure that NZ lacks. It is also geographically and economically proximate to New Zealand in ways that create some natural correlation — which cuts both ways.

From a tax perspective, Australian shares listed on the ASX All Ordinaries are exempt from FIF for NZ individual investors, which means they are taxed on actual dividends received rather than a deemed return. That is a meaningful advantage for income-oriented investors and removes the FIF complexity that applies to other international holdings.

A modest Australian equity allocation — 10% to 15% of total equities — gives NZ investors exposure to a more diversified market, some resources exposure they would not otherwise have, and a tax-efficient way to hold international assets without triggering FIF.

A practical allocation framework

The following is an illustrative starting point for a growth-oriented NZ investor in their 30s or 40s building a long-term portfolio. It is not a recommendation — your specific situation, risk tolerance, time horizon and tax position will all affect what the right allocation looks like for you. An investor closer to retirement would hold significantly less in equities and more in fixed income. An investor with substantial existing property wealth already has significant NZ asset exposure and may want less NZ equities as a result. But for a long-horizon investor starting from scratch, it gives a sense of the proportions I think are defensible.

The 60% global equities allocation would typically be accessed through NZ-domiciled PIE funds — Smartshares funds on InvestNow, or Kernel's global index funds — which handle FIF internally. That keeps the tax position clean for the majority of the portfolio.

The NZ and Australian allocations can be accessed through the same PIE fund platforms or directly through Sharesies. Australian shares are FIF-exempt, and NZ shares are taxed on actual dividends, so neither creates the FIF complexity that applies to other international holdings.

The FIF threshold and how it shapes construction

One practical consideration that shapes portfolio construction for many NZ investors is the $50,000 FIF threshold. Investors with overseas holdings below that threshold at cost are exempt from FIF entirely — they pay tax only on actual dividends and realised gains from overseas shares.

For investors building toward that threshold, there is a structural argument for keeping direct overseas holdings below $50,000 and accessing additional international exposure through NZ-domiciled PIE funds. Above the threshold, FIF applies to the whole overseas holding, so the calculus changes and the right approach depends on the size of your portfolio and whether FDR or CV produces a better result in your specific year.

Currency hedging: a brief note

As I covered in Week 1, currency is a genuine variable for NZ investors that US-centric content ignores entirely. For the global equities portion of a portfolio, the choice between hedged and unhedged funds matters over time.

The short version: unhedged funds give you full exposure to currency movements, which can add or subtract 10% to 20% in a given year. Hedged funds reduce that variance but come at a cost, typically 1% to 2% per year, which compounds significantly over a long investment horizon. For a long-term investor with a 20-plus year horizon, the compounding cost of hedging is a meaningful drag. For an investor with a shorter horizon or lower tolerance for currency volatility, hedging makes more sense.

Smartshares offers both hedged and unhedged versions of most of its major international funds. Kernel's global funds are unhedged. Neither is automatically right. The relevant question is how much currency variance you are comfortable with and over what time frame.

Putting it together

Portfolio construction does not need to be complicated. For most NZ investors, a straightforward approach works well: a globally diversified equity core accessed through NZ-domiciled PIE funds, a modest NZ and Australian equity allocation, and enough stability from bonds or cash to avoid being forced to sell equities at the wrong time.

The NZ-specific considerations — FIF, the home bias problem, currency, PIE fund structures — add layers that US-centric content cannot help with. But once you understand them, they become part of how you think about construction rather than obstacles to it.

Next week I will cover KiwiSaver strategy specifically: how to think about fund selection, the fee and return trade-off between active and passive funds, and how your KiwiSaver allocation relates to your broader investment portfolio.