Tri Mahesa Rahayuningtias, Merry Sukartini, Desty Cristya Anisa
This study compares the Cost of Debt, proxied by Yield to Maturity (YTM), between Green Bonds and conventional bonds issued by energy-sector firms in Indonesia, Malaysia, and Singapore during 2021-2025. Amid the global energy transition and rising demand for sustainable financing, it remains unclear whether the “green” label translates into a lower cost of capital for issuers, a phenomenon known as the Greenium. Using a matched-pair sampling technique, 30 Green Bonds were paired with 30 conventional bonds sharing similar issuer characteristics, tenor, and credit rating, yielding 60 observations. Data normality was confirmed with the Shapiro-Wilk test, and mean differences were examined using the Paired Samples T-Test, both for the pooled ASEAN-3 sample and for each country separately. The results show no statistically significant difference in YTM between Green Bonds (mean 5.35%) and conventional bonds (mean 5.05%) at the regional level (Sig. = 0.353), a pattern that also holds for Indonesia, Malaysia, and Singapore individually. Consistent with the Efficient Market Hypothesis, these findings suggest that green labeling alone has not yet produced a measurable Greenium in ASEAN-3 energy bond markets, implying that credibility-building measures beyond labeling are needed for green instruments to meaningfully lower issuers' cost of financing.