re: Question about buying Vanguard fund...

If you execute a buy and sell (or sell and buy) within 60 days of each other most funds will either impose a hellacious fee or prohibit it altogether.

That said, many funds are very similar, you could for example sell a Vanguard fund that tracks the Wilshire 5000 and then the next day buy the equivalent fund from some other family. Obviously you are limited by the number of such funds out there but you can get around it occasionally that way if you need.

Otherwise yes it does trade basically like any other fund (or stock if it is an ETF). You have to wait 60 days but otherwise you just buy or sell as you like.