Loading aggregates on reacting to domain events

will help you There are a couple of ways to handle this situation, but the basic idea is that you want the triggers for your AJAX requests to come from changes to your view model.
If you want to trigger an AJAX request based on the change to a single observable, then a manual subscription is a good choice.

var trigger = ko.dependentObservable(function() {
    //access any observable that you want to trigger re-evaluation.  You don't even need to do anything with their values.
    valueOne();
    valueTwo();
    valueThree();

    //trigger AJAX
});

seems to work fine You might have to override acceptsFirstResponder, and return YES. Also, you might need to click in your view ( or whatever it is you subclassed) to have it not beep. I've tested this, and sometimes, it seems necessary to do these things, and sometimes not.

fixed the issue. Will look into that further First of all: Do not use Add() to withdraw. DDD is all about following the domain. And I don't think that you say So when I add a negative amount of money to account A, the equal amount will be added to account B when you talk to the product owner. Add a Widthdraw method.

will be helpful for those in need If you need Event Sourcing, you should store events only.
This should be the sequence:

help you fix your problem I don't think you should design your aggregates with querying concerns in mind. The Read side is here for that.
On the domain side, focus on consistency concerns (how small can the aggregate be and the domain still remain consistent in a single transaction), concurrency (how big can it be and not suffer concurrent access problems / race conditions ?) and performance (would we load thousands of objects in memory just to perform a simple command ? -- exactly what you were asking).