AP3, Stockholm, returned a net 10.8% in the six months ended June 30, while assets increased by 9.8% to 374 billion Swedish kronor ($40.2 billion) over the two quarters.
For the year ended June 30, assets increased 5.9%.
The pension fund said in an update Thursday the return equated to a gain of 36 billion kronor for the six-month period. That compared with a 3.3%, or 11.2 billion kronor, gain for the first half of 2018.
The annualized net return for the five-year period ended June 30 was 8.6%; the 10-year annualized return was 9.1%.
As of June 30, the pension fund reported that equity returned a net 17.8%; inflation-linked investments, 7.3%; fixed income, 2.2%; and credit, 2.3%. The remaining asset classes recorded flat returns.
"Equity markets made the largest single positive contribution ... to overall return and the fund's real estate investments also performed strongly," CEO Kerstin Hessius said in a news release.
AP3 had 70.4 billion kronor invested in real estate and infrastructure as of June 30.
