In a unanimous opinion issued on May 18, 2015, the Supreme Court confirmed a continuing duty of ERISA trustees to monitor investments. Although the case involved a complicated procedural history before arriving at the Supreme Court, the lawsuit presented a fairly simple question: is it sufficient for the ERISA duty of prudence that the fiduciary make prudent decisions to invest in the first instance, or must the fiduciary also make prudent ongoing decisions about whether it should change the composition of the plan’s portfolio or otherwise sell assets?