ABSTRACT Although graphene has created a strong wave of enthusiasm after its discovery in 2004 and the subsequent Nobel prize awarded to the two detectors in 2010, there is no clear information how people with special interests in it feel toward the possibility of its commercial value over time. The objective of this study is to identify graphene sentiment shift and major discussion topics among the interested public on Reddit by presenting an effective tool for extracting public opinions in social media. To achieve this, we processed 11,287 comments collected from the Reddit from 2010 to 2021, and applied text mining techniques, including sentiment analysis. This study found that over half of the comments were positive toward graphene, and specific sentiment fluctuated commensurate with major events, for example, Nobel Prize, commercialisation delay and wide applications to the industry. Our research proved that public sentiments toward graphene technology follow a similar trend to the hype cycle by deriving a sentiment hype cycle for graphene. This study provides a convincing case for understanding shifts in the sentiments of the interested public regarding new technology, such as graphene, which will interest graphene technology R&D experts and policy-makers.