In this paper we introduced a case of Proterra, an electric bus manufacturer in Silicon Valley, California. Through the case study, we could clarify the different behavior of Proterra which is an EV maker from inception versus the behavior of fossil fuel vehicle manufacturers that begun to offer EVs. Also we could show the specific characteristics of commercial vehicles that could allow it to transition to EVs more rapidly than the passenger vehicle market. We also explained the effects of Proterra being located in Silicon Valley. Finally we suggested the future scenarios of the EV market.