Use it to finance loans for real estate investments for private investors. There are very few providers of this money but the risk is very low (maximum of 70% of the value in a state as if the property is rented out). Combine this with sustainable propertys (A or B energy level) or finance the upgrading of the energy label combined with it.

Low risk, high profit + more sustainability = lower Costs for bunq premium?

Lownrisk