Most KiwiSaver funds posted negative returns in the first three months of this year after a drop in share markets around the world, according to Morningstar.
The S&P/NZX 50 dropped 0.9 per cent in the first quarter while global shares fell 2.7 per cent in the MSCI Global Index.
Chris Douglas, Morningstar's manager of research ratings, said volatility had returned to global markets during the first quarter of 2018 and the strong performance of share markets around the world came to an abrupt halt.
"As a result, any KiwiSaver Scheme with a bias to equities was more likely to post a negative result," he said.
The average return for the conservative category was just 0.37 per cent while the average for the aggressive growth sector, which invest the most in shares, was a loss of 2.58 per cent.
But the rough ride for the quarter was not enough to pull one-year returns into the red.
"Pleasingly, all KiwiSaver funds managed to produce positive returns over the year across the multisector categories," Douglas said.
The average return for conservative KiwiSaver funds over the year to March 31 was 4.37 per cent, while the average for the balanced sector was 6.6 per cent.
The growth sector averaged 7.58 per cent while the aggressive growth category had the highest average return at 8.81 per cent for the year.
Morningstar's quarterly report shows the amount of money invested in KiwiSaver has risen from $38.8 billion to $46.5 billion over the year.
ANZ remains the largest provider with a 25 per cent share of the market and $11.7 billion in funds under management.
ASB is the second largest with a market share of 18.3 per cent and $8.5 billion and Westpac is third largest at 12 per cent with $5.6 billion.