https://www.wsj.com/articles/cathie-woo ... investor_t (apologize if behind paywall for you)What’s happened at ARK is a counterblast to the belief that ETFs are superior in every way to mutual funds. Over the past decade, investors have been stampeding into ETFs—which are, on average, much cheaper and more tax-efficient than mutual funds. ETFs have one critical flaw, however: They can get too big too fast, and nobody can stop it.
Nearly all professional investors admit—at least in private—that success carries the seeds of its own destruction. It’s a lot easier to rack up giant gains with a small fund than with a big one.
A mutual fund can mitigate this problem by closing to new investors, shutting off the inflow of cash. Over the years, when hot new money threatened to bloat mutual funds to unwieldy size, such firms as Fidelity, T. Rowe Price and Vanguard closed some of them until markets cooled off.
What is actionable? If one chooses to use active management, consider this advantage of traditional mutual funds as compared to ETF's.