Dayang Anna Anjelina. The Effect of CSR Performance on Investment Efficiency with Business Strategy as a Moderating Variable (Empirical Study on Southeast Asian Emerging Countries for the Period 2020-2022). Supervised by Mrs. Mega Norsita. Using unbalanced panel data of 381 observations from 210 non-financial enterprises in developing nations in Southeast Asia, this study utilized to determine how a company's CSR performance increased the efficiency of its investment amid financial crises such as the COVID-19 pandemic. Using EViews 10 and IBM SPSS 25, CSR performance was proxied with ESG scores from the Thomson Reuters database weakened underinvestment by decreasing information asymmetry. Furthermore, it was shown that the Prospector and Defender strategies also had an impact on the company's investment efficiency; specifically, the Prospector strategy aims to enhance underinvestment, whilst the Defender approach will intensify these conditions. Finally, the researchers discovered that both the Prospector and Defender strategies had a pseudo-moderating effect on the relationship between CSR performance and investment efficiency during the COVID-19 pandemic. The company's investment efficiency would be negatively impacted by the prospector's strategy when it is integrated with its CSR performance, but positively impacted by the defender's strategy when it is integrated with its CSR performance.