(13)In order to allow investment firms to continue to rely on their existing own funds to meet their own funds requirements under the prudential framework specific to investment firms, the definition and composition of own funds should be aligned with Regulation (EU) No 575/2013. This includes full deductions of balance‐sheet items from own funds in accordance with Regulation (EU) No 575/2013, such as deferred tax assets and holdings of capital instruments of other financial sector entities. However, investment firms should be able to exempt non‐significant holdings of capital instruments in financial sector entities from deductions if held for trading purposes in order to support market making in those instruments. In order to align the composition of own funds with Regulation (EU) No 575/2013, the corresponding ratios of the types of own funds have been mirrored in the context of this Regulation. To ensure that the requirements are proportionate to the nature, scope and complexity of the activities of the investment firms and that they are readily accessible to the investment firms within this Regulation, the Commission should review the appropriateness of continuing to align the definition and composition of own funds with that of Regulation (EU) No 575/2013.