Blockchain mania occurs in response to the quick rise of Bitcoin price in markets with cryptocurrencies circulation. However, Chinese government policies regarding the development of blockchain are inconsistent--block access to the offerings and exchanges of cryptocurrencies such as Bitcoins, but raise the blockchain technology to a strategic position. We empirically investigate whether the government’s inconsistent policies will lead to blockchain mania and how it affects the blockchainrelated firms’ activities and performance. Our results are threefold: First, the supportive policy can fully offset the negative effect due to the national boycott of cryptocurrencies. Second, Nonspeculative firms experience a stronger and long-standing positive reaction, while the effect on Speculative firms is transient and vanishes after receiving a definitive warning ten days later. Third, the market reaction to government support appears more pronounced among firms having established blockchain technology alliances, or being endorsed officially.