Vanguard, on their page which lists the 30 day average bid/ask spread for their various ETFs, currently has 0.02% and $0.02 as the spread for VTI:

Vanguard 30-day bid/ask spread

However, if I lookup VTI on Morningstar, it has a bid/ask spread of $2.31, or 2.19%.:

enter image description here

Is it really true that the current bid/ask spread is over 115 times the 30-day average? Why is Morningstar's quote for the current bid/ask spread number so much larger than the 30-day average listed by Vanguard?

1 Answer 1


The bid/ask spread changes constantly (even on heavily traded funds or securities); right now the B/A/S was 0.02% when I checked a few minutes ago, and is now 0.05%. That's why Vanguard gives the average 30 day B/A/S (and probably specifically the average during market open periods).

I guess you just looked in at a time that happened to have few people interested in buying or selling VTI - perhaps because the market was closed when you checked, and with the market heading down there wasn't too much interest in selling until it's clear whether the market was going to settle at open or continue down (which it did).

  • Thanks. The bottom line, then, is that the bid/ask spread can indeed go way above the 30 day average. I'm guessing this is more likely to happen during after-hours trading?
    – Josh
    Jan 12, 2015 at 22:01
  • I don't necessarily know in detail the likelihood, but it does seem more likely in after hours trading to have a much larger bid/ask since many fewer trades occur during that time.
    – Joe
    Jan 12, 2015 at 22:02
  • This is only anecdotal, but I've been watching the bid/ask spread the last few days, and when the market is closed it shoots way up, just like in my screenshot. When the market opens, it plummets back down to just a few cents. Based on this tiny sample, then, the huge swings seem to be highly correlated to the market being open or closed.
    – Josh
    Jan 15, 2015 at 13:34

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .