It was a unanimous decision.
The facts of the case are that James LaRue lost $150K after his 401(k) managers ignored his orders to move his holdings to a different account. The lower courts said that only the plan had standing, but SCOTUS said that the participants do to.
Frankly, I’m surprised. I would have figured that one of the court Neanderthals would have taken the side of the incompetent money managers.