Strong share markets have helped push the amount of money invested in KiwiSaver to more than $60 billion - a rise of nearly 18 per cent in the past year.
Figures from Morningstar shows as of September 30 there was $60.9b in the retirement savings scheme, up from $51.7b a year earlier.
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Tim Murphy, director of manager research Asia-Pacific for Morningstar, said all but one of the KiwiSaver funds in its survey made positive returns in the three months to September 30 after a strong run in markets.
"The September quarter saw markets continue to rally, returns of KiwiSaver funds generally reflected the strength of underlying market conditions."
Share market returns in Australia and New Zealand have been particularly strong this year; the S&P/NZX50 index has risen 24 per cent for the first nine months of the year and the S&P/ASX200 index is up 25.6 per cent in New Zealand dollar terms.
Murphy said outside Australasia, international markets have had a bumpy ride in recent months. The MSCI World index was flat in US dollars over the September quarter, but New Zealand investors benefitted from the falling New Zealand dollar.
Top-performing funds for the quarter were Aon Russell Lifepoints in the conservative fund sector, which was up 2.7 per cent, the AMP Income Generator fund in the balanced sector, up 3.5 per cent, and the Juno Growth fund, up 4 per cent in the growth category.
Over the year to September 30, the top conservative sector fund was Simplicity Conservative, with a return of 9.2 per cent. The AMP Income Generator fund was the best performer in the balanced sector at 11.6 per cent, and Juno's Growth fund topped the growth sector at 11.8 per cent.
Murphy said it was most appropriate to evaluate the performance of KiwiSaver by looking at long-term returns.
Over 10 years, the top fund in the conservative category is the Aon Russell Lifepoints 2015 fund, with an average annual return of 7.7 per cent, while the Aon Russell Lifepoints 2035 fund is top for the balanced sector, with an average annual return of 9.8 per cent.
Milford's Active Growth fund remains the top in the growth category, with an average annual return of 12.7 per cent.
ANZ is the largest provide, with $14.8 billion and a 24.3 per cent share of the market, followed by ASB, which has a 18.3 per cent share and $11.1 billion.
Rounding off the top three is Westpac, which has $7 billion and an 11.5 per cent share of the market.
Murphy said the six largest KiwiSaver providers managed about 80 per cent of the assets which Morningstar monitored.