In this paper, we examine whether sovereign green bonds experience yield premiums or greenium in either primary or secondary markets. From August 2012 to December 2022, we employ a matching approach and a two-layer model to determine whether sovereign bonds yield less than their conventional counterparts. Market results are conflicting across the two markets, with negative premiums of 7 bps in the primary market and positive premiums of 3.5 bps in the secondary market. Ratings, currencies, domiciles, and sectors differ. There is a significant negative premium for financial bonds, lower-rated bonds, USD & EUR denominated bonds, and Luxembourg and Philippines-domiciled bonds on the primary market. AA+rating, AUD & SEK-denominated currency, and government activity can explain the majority of this positive premium on the secondary market. Keywords: Sovereign Green bonds; Greenium; Liquidity; Impact investing