Investing in an SMSF starts first and foremost with the “sole purpose test”. This is the rule that says everything the trustee does needs to be aimed at helping members save for retirement. But there are also specific rules about what you can and can’t do with your SMSF investments. The rules not only relate to the actual nature of the investments but also who you buy them from and what you can do with them once your SMSF owns them.