Whether a service provider is a fiduciary under 29 U.S.C. § 1002(21)(A)(i) when it changes the rate of return on a product offered in an employee benefit plan, even though the plan's participants, by virtue of their freedom to withdraw from the product at any time, retain "authority [and] control respecting management [and] disposition" of their assets.

Whether a service provider is a fiduciary under 29 U.S.C. § 1002(21)(A)(i) when it changes the rate of return on a product offered in an employee benefit plan, even though the plan's participants, by virtue of their freedom to withdraw from the product at any time, retain 'authority [and] control respecting management [and] disposition' of their assets