We incorporate your external accounts into our goal projections and related advice if you link them to specific goals. In projecting the performance of these linked accounts, we assume that they are the same type of account and have the same allocation as the Betterment goal to which they are linked. For example, if you link an external account to a General Investing goal with a 90/10 stock-to-bond ratio, we assume that such linked account is also a brokerage account with a 90/10 allocation. ...