Asset managers are eagerly awaiting an S.E.C. decision that would allow mutual funds to also trade as E.T.F.s — potentially changing how trillions of dollars are invested.

Good morning. Andrew here. This Saturday, we take a deep dive into a potentially major shift in the investing world. Ian Frisch, who has been writing about surprising trends in business for a decade, takes us into the $30 trillion question of whether mutual funds can also market themselves as E.T.F.s. Plus, Calum Marsh, a DealBook contributor who has reported extensively on fitness trends and wrote an upcoming book about the history of CrossFit, speaks with the C.E.O. of Hyrox, a global fitness craze that wants to become an established sport.