The article explores how green bonds have a lower risk premium compared to traditional bonds, which can benefit both issuers and investors. By using a unique approach called the Twin-Bond ULFP method, the researchers show that green bonds can be issued at a lower cost while still meeting investors' risk-return expectations. They analyze bond spreads and volatility to understand how green bonds perform compared to traditional bonds. This research can help in pricing new bonds and evaluating the value of existing green bonds in the market. It also suggests that reducing volatility through policy measures could further support green investment projects.