AP4 constitutes part of the Swedish income pension system. The Fund's brief is to support the stability of the national pension system by managing Fund capital with the aim of generating the best possible return over time. Together with AP1, AP2 and AP3, AP4 has two important roles in the national pension system.
The four Funds work partly as a buffer, with the purpose of covering future pension disbursements, and their returns partly contribute to the long-term financing of the pension system. AP6 is also a buffer fund, but is not part of the regular flows of the pension system.