Why "best" depends on you
Most "best KiwiSaver fund" lists rank funds by last year's return. That tells you what already happened, not what suits your situation — and the fund that topped the table last year is often not the one that fits your goals. A better question than "which fund performed best?" is "which fund is right for what I am trying to do?"
Three things shape that answer more than anything else: your timeframe, your goals, and your risk tolerance. Get those right and the fund type usually follows.
1. Your timeframe
Timeframe is how long until you actually need the money. It is the single biggest factor in choosing a fund, because it decides how much short-term risk you can afford to take.
If you are years or decades away from touching your KiwiSaver — for most people, that means retirement — you have time to ride out the bad years. Growth and aggressive funds fall harder in downturns, but they have longer to recover and tend to grow more over the long run. A short-term dip matters far less when you are not selling for twenty years.
If you need the money soon — buying a first home in the next year or two, or close to retirement — a large fall at the wrong moment can do real damage, because you do not have time to wait for it to bounce back. Shorter timeframes usually call for more conservative funds, where the ride is steadier even though long-run growth is lower.
2. Your goals
What you are saving for changes the answer. Retirement decades away is a very different goal from a first-home deposit you will withdraw next year, even for the same person.
Many people are working toward more than one goal at once, and the money for each may belong in a different place. It is common to have a long retirement horizon that suits a growth fund, while a near-term first-home deposit sits better in something more conservative. Being clear on the goal — and its timeframe — is what points you to the right fund.
3. Your risk tolerance
Risk tolerance is how comfortably you can sit through a fall in your balance without losing sleep or switching at the worst possible moment. It is part maths and part temperament.
Growth and aggressive funds are mostly shares, so a fall of 20–30% in a bad year is a normal event, not an emergency. On paper a long timeframe might suit that kind of fund — but if watching your balance drop that far would push you to panic and switch to cash, locking in the loss, then it is the wrong fund for you regardless of the timeframe. The best fund is one you can actually stay invested in through a downturn.
This is where honesty with yourself matters. The right fund on a spreadsheet is worthless if you cannot hold your nerve when markets fall.
Putting it together
Choosing well is not about finding a single magic fund — it is about matching the fund type to your timeframe, being clear on your goals, and being honest about how much risk you can genuinely live with. From there, comparing fees and returns across the whole market narrows it down to the right specific fund.
This is exactly what an adviser does with you: work through your situation, land on the fund type that fits, and compare the market to find the one that suits — at no cost to you.