Financial market volatility at the start of the year has dented returns for most KiwiSaver investors.
Sharemarkets around the world fell in the first three months of the year as rising interest rates, trade tensions, and data protection issues hit investor sentiment and stocks.
The benchmark New Zealand top-50 index fared better than many sharemarkets, falling less than 1 percent for the quarter. One global market index fell by 2.7 percent.
Investment research company Morningstar Asia-Pacific manager Chris Douglas said the first quarter of the year was negative for most funds exposed to shares, and those that chased riskier, high returns fared worse.
"KiwiSaver funds with a bias to defensive assets outperform their growth-minded counterparts," Mr Douglas said.
"Equity markets posted negative results over the first three months of 2018, while cash and fixed interest posted small yet positive returns.
"As a result, most KiwiSaver funds posted negative returns, especially those in the higher risk profiles."
However, on an annual basis most KiwiSaver funds had positive returns.
The average return for conservative KiwiSaver funds for the year ended March was 4.37 percent, for balanced funds it was 6.6 percent, and for growth sector funds the average return was 7.58 percent.
The amount invested in KiwiSaver was $46.5 billion, up from $38.8bn the year before.
ANZ was the largest provider with a quarter share of the market, amounting to $11.7bn under management.