Green Investment: Instruments, Drivers, Financial Performance, and the Transformation of Capital Markets

Abstract

Green investment has moved from a niche of ethical finance to a defining force in contemporary capital markets. This paper provides an integrative review of the instruments through which capital is channelled to environmentally beneficial activities, the drivers of demand and supply, the evidence on financial performance, and the market, policy, and measurement challenges that accompany the growth of the green segment. We begin by defining green investment and mapping its principal instruments, from green bonds and green loans to green equities, funds, and supporting hybrid instruments. We then examine the demand-side drivers, including climate risk awareness, investor preferences, and regulation, and the supply-side factors that shape issuance. We synthesize the empirical literature on green asset pricing and performance, distinguishing the measured "green premium" from the expected-return logic that emerges when investors value sustainability. We analyse how climate risk enters portfolios and how ESG data, ratings, and divergences among them condition investment decisions. We assess the implications of green investment for corporate behaviour and for the design of policy and regulation, and we identify persistent challenges such as greenwashing, fragmentation of standards, and the uneven development of green markets in emerging economies. We conclude that green investment has real potential to mobilize capital for the transition to a low-carbon economy, but that its effectiveness depends on credible measurement, harmonized standards, and a regulatory architecture that aligns private returns with environmental objectives.