According to the Organization for Economic Co-operation and Development (OECD), the model investment agreement expanded the scope of investment. Investment was defined as any asset or resource that is placed for the purpose of making a profit. The multilateral agreements on the promotion and protection of investments (ASEAN) signed in 1987 by Brunei, Singapore, Thailand, the Philippines, and Malaysia offer the broadest definition of investment, which includes all forms of assets. Although the concept of investment is important for ICSID arbitration, it is not defined in the ICSID Convention. As a result, if it is determined that the case concerns a foreign investment, the investor can demand compensation through arbitration due to the restriction of the investment. Arbitral tribunals operating within the framework of the ICSID Convention have over time established standards that are considered typical features of the concept of "investment". In this context, the "Salini test" is often referred to, which distinguishes four main elements related to investment:

1) Significant (specific) contribution;

2) A certain duration (temporal dimension of the operation/project);

3) The existence of risk;

4) Contribution to the development of the host state.

In Georgia, the concept of investment is defined by the Law of Georgia "On Promotion and Guarantees of Investment Activity", according to Article 1 of which, all types of property and intellectual values or rights that are invested and used for the purpose of obtaining possible profit in entrepreneurial activity carried out on the territory of Georgia are considered as investment. Accordingly, for a certain asset to be considered an investment, the law establishes several necessary criteria. These are: 1) For the purpose of profit. That is, investing must aim to make a profit. 2) The investment must be carried out on the territory of Georgia. 3) The investment must be made for the purpose of carrying out entrepreneurial activity. Furthermore, it is clarified that both rights and all types of property and intellectual values are considered as investment. It can be said that to determine the concept of investment, Georgia chooses the so-called general approach and does not establish an exhaustive list of activities of what is considered an investment. As for values and rights, paragraph two of Article 1 establishes that, for the purposes of investment, a value or right can be funds, share, stocks, and other securities, as well as real and movable property, land, buildings, equipment, and other material value. In addition, an investment can be the right to use land or other natural resources (including concession), patent, license, "know-how", experience, and other intellectual value. Furthermore, an investment can be another property or intellectual value or right, if it is not prohibited by legislation.

An international investor is a natural or legal person who exports capital or other assets from one state to another and this transaction has the character of an investment. If the matter concerns an ICSID arbitral tribunal, the definitions of an investor provided in bilateral investment treaties must always be read together with the ICSID Convention, because the determination of the investor's nationality by the arbitral tribunals is made in accordance with the Convention.

The Court of Justice of the European Union (CJEU), with its decisions, especially the Achmea verdict and subsequent decisions, had a significant impact on the overall picture of intra-EU investment arbitration. These decisions established a clearly negative position towards intra-EU investment arbitration, as a result of which the termination of bilateral investment treaties (BITs) between the member states of the European Union began, and the sustainability of arbitration based on multilateral treaties was also threatened. This judicial approach reflects a broader strategic realignment of the European Union: namely, the European Union strives for the resolution of investment-related disputes within its borders to take place more within the internal legal framework of the European Union, rather than through international investment arbitration.