The active investment portfolio is your investments and your current balance summed. For example, if you have 9 000 Eur invested and 1 500 Eur available, your active investment portfolio would account for 10 500 Eur.
When calculations for a possible upgrade to a loyalty category would happen, you would be included in the Silver loyalty category. An additional interest bonus of +0.5% would automatically be applied to all your new investments.