Vanguard ETF expense ratios are almost always^* exactly equal to the corresponding admiral type funds. The reason is because Vanguard holds a patent on the dual

Vanguard ETF expense ratios are almost always^* exactly equal to the corresponding admiral type funds. The reason is because Vanguard holds a patent on the dual-share class[1] idea, where the ETF and admiral share mutual fund are precisely the same fund. *: The exceptions tend to be new-ish funds which are less liquid and have purchase costs on the mutual fund side. I haven't seen more than one or two of these recently. [1]: http://www.ft.com/cms/s/0/3e0cc962-ec0c-11e4-b428-00144feab7de.html http://www.ft.com/cms/s/0/3e0cc962-ec0c-11e4-b428-00144feab7...