Vanguard runs etfs mostly, so I'm not sure why they care about support small spreads since they probably do a lot of efp trades (I'm not sure how the underlying prices are determined, but I think they can convert at a set price). The mutual funds and hedge funds who are more fundamental will try and buy or sell large blocks, so they're more affected by adverse market moves from trying to dump $1M of apple. I could see VG's attitude change a little since there are more traders engaged in rebalancing arb. If you know that the S&P index has to allocate more money to a certain stock, you can buy it ahead of time and sell to VG for a slightly higher price. If you're a passive fund with $1B in an etf, everyone knows what you're obligated to do. It's basically stat arb with higher probability. I still buy VG funds though
Vanguard has something like three trillion dollars under management, only 450Bn of which are ETFs. Vanguard is not the largest ETF provider, but has long been the #1 mutual fund provider. Anyone who rebuts an argument about Vanguard's role in the mutual fund industry by saying "Vanguard mostly runs ETFs" doesn't know what Vanguard is.
