Optimism in global markets has driven an improvement in the value of KiwiSaver assets in the first quarter of the year.
Morningstar's survey for the three months ended March showed the value of savings rose about $4 billion to $108.6b.
Quarterly returns ranged from 2 percent for conservative funds to 8.8 percent for aggressive funds.
Among the key trends affecting New Zealand investors were inflation and global interest rates, Morningstar said.
"Central banks, including the Reserve Bank of New Zealand, took a wait-and-see approach, holding interest rates steady. This signalled some progress in taming inflation, although concerns remained," Morningstar said.
International shares performed well in the quarter, with strong US corporate earnings and enthusiasm for technology stocks, it said.
On the economic front, New Zealand's economic growth was likely to be slow, but the US economy continued to be a bright spot.
"Overall, the first quarter offered a chance for cautious optimism. While inflation remained a concern, global growth prospects improved, and equity markets delivered strong returns, particularly for unhedged holdings due to the weaker NZ dollar," Morningstar said.
Over the past 10 years, the aggressive category gave investors an annual return of 9.1 percent, followed by growth at 8.4 percent, balanced at 6.8 percent, moderate at 4.8 percent and conservative at 4.3 percent.
ANZ continued to lead the market share with $20.4b in assets, followed by Fisher Funds ($16.7b), ASB ($16.6b), BT-Westpac ($10.7b) and Milford Asset Management ($8.6b).