The New Zealand Superannuation Fund grew by 1.88% in Feburary, with a net gain of $296 million.
The fund was established by the last Labour-led government to help pay for the future cost of superannuation.
Data released on Wednesday shows the fund made a 17.24% return for the year to date, and now stands at $15.94 billion.
Feburary's positive result came after a poor January, during which the fund lost 1.97%.
The Government suspended further contributions to the fund in last year's Budget.