A balanced fund. There is a temptation to think that a generic, old-fashioned balanced fund that does not take age into must violate fiduciary duty, and maybe someone will claim that, and even claim that successfully (some courts will do anything), but how can that be? Before the 404(c) regs in the late 80's, many plans had just one fund, and ERISA really assumes there will be one fund, with 404(c) being the exception that has swallowed the rule. Amending a plan to make it self-directed is at least traditionally viewed as a settlor function, not fiduciary, although if someone wanted to pay me to do it I might try to argue that given the easy of implementing self-direction in today's market, and its obvious advantages for a diverse labor force, the decision not to be a 404(c) plan was fiduciary.