Hmmm. I wonder who is "dead wrong" here: Delegge? or Bogle?
I think both interpret the data or use selective points to suit their viewpoints. Bogle points out that SPY is the most traded ETF in the world. Who cares? It's also the oldest ETF, mostly widely known ETF, has liquid options, etc. To echo the point above me, it doesn't matter at all to me if a hedge fund is the primary holder of an ETF.
The only ETFs I would consider that sometimes have a persistent premium/discount to NAV are those that also have a purchase/redemption fee to transact, such as VSS.
DeLegge exaggerates Bogle's position and accuses him or not understanding them, perhaps willfully. This seems an extreme distortion of Bogle's position, as Bogle pointed out with quotes from his book.
I think one of the biggest advantages of ETFs, which neither specifically addresses, is that it's easier to TLH. For example, I have the I Fund in the TSP, so I hold VWO in taxable. If I had a TLH opportunity, it would be far more difficult to execute it if I was limited to mutual funds. Vanguard has only one Emerging Markets fund. With ETFs, I can easily swap VWO for SCHE or IEMG. On top of that, IEMG has the same expense ratio and covers 99% market capitalization, versus 90% for VWO!
ETA - And even with the multitude of ETFs out there following crazy indexes, you still have Schwab and iShares promoting their broadest, lowest cost ETFs as Core ETFs. I don't think there's that
many investors choosing a 2x S&P 500 ETF for a core holding. Additionally, the Vanguard study cited in both articles may confuse cause and effect. Maybe ETF investors trade slightly
more frequently because they would have been predisposed to that anyway. They might have traded more frequently with mutual funds. In some ways, it's more
difficult to trade ETFs. You have to do it while the market is open, you're stuck with whole shares, and you can't auto-invest easily. Admittedly, I haven't read the study and don't know if the Vanguard research team considered these possibilities.