[crazygringo]

Very true. But on the other hand, it ties up your investments for several days.

Moving means totally removing yourself from the market precisely at the time when big swings are happening, which many people might not want to risk. So it's actually pretty tricky, not frictionless or anything.

[r00fus]

You migrate your new buy activity into Fidelity and leave your existing stock in RH (you can still sell).

At some point, either migrate your holdings from RH completely or sell them off and move money to Fidelity.

Done.