Capital markets have changed profoundly since green bonds were first introduced in 2013 as a way of financing programs benefiting social and environmental sustainability. The purpose of this study is to investigate whether green bond issues are related to value creation as compared with conventional bond issues, and how the relative size of a bond issue may impact this relationship. Using bonds issued on Nasdaq Stockholm from 2014 to 2020, our study finds no significant abnormal returns for green bonds, the benchmark of conventional bonds nor the comparison of the means. Further, we could not find an interaction effect between the relative issue size and the green bond. Hence, this study finds no indication that green bonds create value. However, we show that relative size has a positive and significant regression coefficient in all models, meaning that the larger the relative size of a bond issue, the more the stock price is expected to increase.