In fact, some critics argue, despite improving returns, active funds may never fully reverse their decline in popularity. One key factor: The success of new investments like ETFs, which encourage a style of investing that involves betting on segments of the market rather than individual stocks, and which also put a relentless emphasis on investment costs. ETF companies haven’t been shy about touting the importance of keeping costs down in newspaper ads and conference speeches, and many think that lesson may now never be unlearned. “People are more conscious about fees,” says Michael Rawson, an analyst at researcher Morningstar.