Gas fees are a core cost indicator in the cryptocurrency market (especially in the Ethereum ecosystem), and their fluctuations directly impact on-chain activity and market sentiment. They may serve as one of the auxiliary indicators for assessing bull and bear cycles, but should be evaluated in conjunction with other data.

1️⃣ Market activity and cost pressure: When gas fees surge, the transaction costs for users skyrocket, which may suppress high-frequency interactions such as DeFi and NFTs, leading to a decline in on-chain activity, reflecting an overheated or congested market (e.g., the median gas fee exceeded 200 Gwei during the peak of the 2021 bull market); conversely, persistently low gas fees (e.g., dropping below 20 Gwei in 2024) may indicate a cooling market or the effectiveness of expansion solutions (e.g., the popularization of Layer 2). If this is accompanied by a shrinking trading volume, it could be a signal of a bear market.