Index funds are the most important investment tool available to New Zealand investors. They’re simple, cheap, tax-efficient, and consistently outperform the majority of actively managed alternatives over the long run.
An index fund tracks a market index (like the NZX 50 or S&P 500) and holds all or most of its companies. Instead of a fund manager picking stocks, the fund simply mirrors the index — at very low cost. For most NZ investors, the best options are: InvestNow Foundation Series (0.20%), Simplicity Growth Fund (0.10%), or Kernel High Growth Fund (0.25%). Minimum investment: $1 (Kernel), $250 (InvestNow), $1,000 (Simplicity).
What Is an Index?
A market index is a list of companies that meets certain criteria (size, liquidity, geography). Common indices include:
| Index | What it tracks | Companies |
|---|---|---|
| NZX 50 | 50 largest NZ companies | ~50 |
| S&P 500 | 500 largest US companies | 500 |
| MSCI World | Large/mid-cap developed markets | ~1,500 |
| MSCI All Country World (ACWI) | Developed + emerging markets | ~2,900 |
| Bloomberg NZ Bond Index | NZ government and corporate bonds | Varies |
What Is an Index Fund?
An index fund holds the same companies as the index, in the same proportions (weighted by market capitalisation). If Apple makes up 7% of the S&P 500, an S&P 500 index fund holds approximately 7% of its assets in Apple.
There’s no stock-picking. The fund simply follows the index rules. This is called passive management.
Why Index Funds Beat Active Funds (Usually)
Three reasons explain why index funds outperform most active funds over long periods:
1. Lower fees
Index funds cost 0.10%–0.35% p.a. in NZ. Actively managed funds cost 0.80%–1.50% p.a. The difference compounds dramatically:
| Fee | 20-year cost on $100,000 (8% gross return) |
|---|---|
| 0.10% index fund | ~$4,800 lost to fees |
| 1.10% active fund | ~$49,000 lost to fees |
2. Market efficiency
In large, well-followed markets (S&P 500, MSCI World), share prices quickly reflect available information. It’s extremely difficult for any manager to consistently find and act on information others don’t have.
3. Survivorship bias
When we compare active funds to indices, we only see the active funds that survived — the underperformers close down and disappear from the data. The average active fund performance looks better than reality.
Best NZ Index Funds (2026)
For global exposure
| Fund | Provider | Index | Fee | Minimum |
|---|---|---|---|---|
| Foundation Series International Shares Fund | InvestNow | MSCI World | 0.20% | $250 |
| Foundation Series Total World Fund | InvestNow | MSCI ACWI | 0.25% | $250 |
| Kernel High Growth Fund | Kernel | Global blended | 0.25% | $1 |
| Kernel Global 100 Fund | Kernel | MSCI Global 100 | 0.25% | $1 |
| Kernel S&P 500 Fund | Kernel | S&P 500 | 0.25% | $1 |
| Simplicity Growth Fund | Simplicity | Global + NZ blended | 0.10% | $1,000 |
| Smartshares Total World Fund (TWF) | Smartshares/NZX | MSCI ACWI | 0.20% | $500 |
For NZ shares exposure
| Fund | Provider | Index | Fee | Minimum |
|---|---|---|---|---|
| Foundation Series NZ Shares Fund | InvestNow | NZX 50 | 0.20% | $250 |
| Smartshares NZ 50 ETF (NZG) | Smartshares/NZX | NZX 50 | 0.20% | $500 |
| Kernel NZ 20 Fund | Kernel | NZX 20 | 0.25% | $1 |
For balanced exposure (shares + bonds)
| Fund | Provider | Allocation | Fee | Minimum |
|---|---|---|---|---|
| Foundation Series Balanced Fund | InvestNow | 60% shares / 40% bonds | 0.29% | $250 |
| Simplicity Conservative Fund | Simplicity | 35% shares / 65% bonds | 0.10% | $1,000 |
| Kernel Cash Plus Fund | Kernel | Short-duration bonds | 0.25% | $1 |
How Index Funds Are Taxed in NZ
Most NZ index funds are structured as PIE funds (Portfolio Investment Entities). Tax is deducted at your PIR rate — capped at 28%, regardless of your marginal income tax rate (which can be up to 39%).
PIR rates:
- 10.5% — household income under $14,000
- 17.5% — household income $14,001–$48,000
- 28% — household income over $48,000
No need to file a tax return for PIE fund income — tax is final (handled by the fund).
→ See: PIR Rate NZ — How to Check and Set Yours
Index Fund vs ETF — What’s the Difference in NZ?
Both can be index funds (passive). The difference is how you access them:
| Index Fund | ETF | |
|---|---|---|
| Access | Direct via platform (InvestNow, Kernel) | Bought/sold on an exchange (NZX) |
| Pricing | End-of-day NAV | Real-time during trading hours |
| Minimum | Usually $250–$1,000 | Usually $500 |
| Example | Foundation Series International Shares | Smartshares Total World Fund (TWF) |
For regular automated investing, directly-accessed index funds (InvestNow, Kernel, Simplicity) are easier — you set an auto-invest amount and the platform handles the rest.
→ See: ETF vs Managed Fund NZ — Key Differences
How to Invest in an NZ Index Fund: Step by Step
Via InvestNow (Foundation Series)
- Go to investnow.co.nz and create an account
- Verify identity (NZ driver licence or passport)
- Link a bank account
- Choose the Foundation Series International Shares Fund
- Set your initial investment amount ($250 minimum)
- Set up a regular investment plan (as low as $50/month)
Via Kernel
- Go to kernelwealth.com and sign up
- Verify identity
- Choose fund (High Growth, Global 100, S&P 500, etc.)
- Invest from $1 immediately
- Enable auto-invest
Via Simplicity
- Go to simplicity.kiwi
- Choose Growth, Balanced, or Conservative
- Minimum $1,000 to open
- Regular contributions from $50/month
Common Index Fund Mistakes
Checking performance too often. Index funds are long-term vehicles. Daily checking creates anxiety and bad decisions.
Switching when markets drop. Selling during a downturn locks in the loss. Index funds recover — if you hold.
Choosing the wrong risk level. A growth fund in a savings account is wrong. An index fund for a 5-year goal requires a more conservative allocation.
Paying too much. The fee difference between 0.10% and 1.10% costs $44,000 over 20 years on $100,000. Choose low-fee funds.
Frequently Asked Questions
Are index funds safe? No investment is “safe” in the sense of guaranteed returns. Index funds hold shares and can fall 30–50% in a market crash. They’re appropriate for investors with a long time horizon (5+ years) who can ride out volatility.
Can I lose all my money in an index fund? To lose all your money in a global index fund, every major company in multiple countries would need to simultaneously go to zero — essentially a scenario where money itself has no value. It’s extremely unlikely. A concentrated single-company investment can go to zero; a diversified global index fund cannot.
Do index funds pay dividends? NZ PIE fund index funds typically accumulate dividends within the fund (reinvest them automatically). Your fund value grows; you don’t receive separate dividend payments. This is efficient for NZ investors.