How do I figure out how much it costs to exchange a fund or ETF within the same retirement account?
Example: I want to exchange $100 worth of VTSAX and change it to $100 worth of VOO.
Vanguard shows this as a no-commission transaction, but there are fees somewhere, right?
Vanguard's patented process only allows converting mutual fund shares to ETF shares.
VTSAX can only be converted to VTI. Vanguard has a patent on pooling mutual funds and ETF assets together, which is why Vanguard can perform a mutual fund to ETF conversion (VTSAX to VTI). Vanguard won't allow you to convert in the other direction.
I’ve assumed that they just shaved some amount off when they sold and that I end up with slightly less than $100 of VOO.
No sale occurs. Vanguard holds VTSAX and VTI assets as separate share classes of the same pool of assets. When you exchange VTSAX into VTI, Vanguard updates their accounting records, moving your holdings from one class of shares to another. You start and end with the same amount of assets.
All true, but OP was asking about VTSAX to VOO (not VTI) and using the word "exchange". "Exchange" is just Vanguard's term for a sale "immediately" followed by a buy. So in the case of VTSAX to VOO, there would actually be a sale (with associated tax ramifications if in a taxable account) followed by a buy. Still zero commission if done at Vanguard, I think.
Vanguard's account menus have options to "trade", which is what you're describing, and to "exchange", which moves money between two selected mutual funds. I assumed OP knew how to sell something, and so was asking about something more complex, like conversion between share classes. In the forum, people have asked about converting Vanguard mutual funds to ETF equivalents before, but I don't recall anyone asking how to sell something. So I assumed this was a more complex question about converting.
One thing I don't know of is the exact speed of the transaction. When I exchange Vanguard mutual funds, it happens after the close at the closing price. I assume the sell of VTSAX would happen after the close, but I don't know when and what price you'd get on the VOO purchase. Maybe the closing price that same day?
I don't think this is supported on Vanguard's website. It has been years since I held mutual funds in my Vanguard account, so maybe I'm out of date.
Mutual funds are only priced after the market closes, which is also when Vanguard would handle purchases and redemptions for VTSAX. Since that happens when the market is closed, they can't buy ETF shares at that time. As far as I know, Vanguard doesn't support after-hours trading of ETF shares. I also think any purchase of an ETF has to be performed manually by the customer, which also makes me think this can't happen automatically. There is no ability to automatically purchase ETF shares at Vanguard, as far as I know.