The New Zealand Superannuation Fund has posted a 13.9 per cent return for 2014, finishing the year at $27.5 billion, but warns returns will be "more muted" over the coming years.
Stock markets around the world performed strongly last year, continuing what has now been an almost six-year bull market for equities.
Chief executive Adrian Orr said a heavy weighting to global equities and a decline in the New Zealand dollar's strength had helped the fund deliver strong returns.
The fund's 13.9 per cent total return exceeded a 12.4 per cent return from its passive reference portfolio and a 3.1 per cent return for Treasury bills - a measure of the cost to the Government of contributing to the fund instead of paying debt, the Super Fund said.
Orr said future returns were unlikely to be as strong as in 2014.