Securing Employee Retirement Returns Act This bill revises the fiduciary duties for a retirement or employee benefit plan that is regulated under the Employee Retirement Income Security Act of 1974. The bill generally requires a fiduciary to select and maintain investments for a plan based solely on pecuniary factors. Under the bill, a pecuniary factor is a factor that is expected to have a material effect on the risk or return of an investment based on appropriate investment horizons that are consistent with the plan's investment objectives and funding policy. The bill allows a fiduciary to use nonpecuniary factors in certain circumstances, such as when a fiduciary (1) is unable to distinguish between investment alternatives on the basis of pecuniary factors alone, or (2) is selecting or maintaining investment alternatives for a defined contribution plan that permits a participant or beneficiary to choose from a broad range of investment alternatives.