most of your articles and learned a great deal. Just an aside though... You say that "The most liquid ETFs have spreads of just a penny". This isn't always the case. With higher priced ETF's you would expect proportionally higher spreads. For example VTI trades at about $75.00 per share, so a reasonable bid-ask spread would be triple that of a similar $25.00 per share ETF. Similarly a $10.oo per share ETF should have a very tight bid-ask spread. I believe also, that early ETF companies sometimes give temporary incentives in the form of a MER discount to make up for large bid-ask spreads. Not sure how common this is though.