Determination of investment is an important element of international investment law because only qualiﬁed investments are protected thereunder. Traditionally, deﬁnitions of investments have taken either an asset-based or an enterprise-based approach. Brieﬂy, an asset-based deﬁnition emphasizes foreign investors’ property interests and rights, whilst an enterprise-based deﬁnition focuses on foreign investors’ participation in and control of the entities established in the host state.1 What is common in contemporary bilateral investment treaties (“BITs”) and free trade agreements (“FTAs”) is the combination of asset-based and enterprise-based deﬁnitions in which what may constitute an investment is stipulated in an illustrative list. However, no BIT or FTA contains an exhaustive list of qualiﬁed investments. As a result, whether a particular transaction is qualiﬁed as a protected investment is subject to interpretation.