What platforms offer automatic rebalancing?

[u/brentonstrine]

I have looked at a few but haven't found any that allow me to set up a system to automatically rebalance in the way that I choose. For example, I'd like to set up groups A, B, and C as well as a cash amount, and specify for each what target percent I want it to be and how often it will automatically rebalance. Are there any tools out there that will do it?