With each passing year, ETFs pull in trillions of dollars while mutual funds steadily bleed assets. And yet, mutual funds still hold more money overall. Now, a long-standing wall between the two may finally be coming down. Dimensional Fund Advisors has launched the first-ever ETF share class of an existing mutual fund, a structure made possible by the expiration of Vanguard’s once-protective patent.

On this episode of Trillions, Eric Balchunas and Joel Weber speak with Joel Schneider, Dimensional’s deputy head of portfolio management for North America, and Katie Greifeld of Bloomberg News. They discuss why Dimensional volunteered to be the guinea pig, why it chose its 45-year-old US Micro Cap Portfolio (ticker: DFMC), and whether this hybrid structure could reshape how trillions of dollars are invested.