Ethereum upgrades follow a three-phase pattern in their impact on ETH prices: "anticipated pre-upgrade rally, short-term correction after implementation, and long-term fundamentals and supply-demand dynamics." The specific effects are influenced by the type of upgrade, market environment, and the degree of expectation absorption.

1. Core Impact Logic

1. Short-term (1-4 weeks before and after the upgrade): Expectations drive speculative buying, leading to a rally, followed by a quick correction as the positive news is priced in; if the upgrade involves staking unlocks, short-term selling pressure may amplify volatility, such as with the Shanghai upgrade or Cancun upgrade.

2. Medium-term (1-6 months): Focus on the actual utility of the upgrade—such as EIP-4844 reducing L2 costs or account abstraction expanding user base—driving ecosystem activity and ETH demand, with prices recovering as fundamentals improve; conversely, if short-term token burns decrease or there is price suppression, the effect may be limited.

3. Long-term (more than 6 months): Deflationary effects strengthen (post-merge issuance drops sharply + EIP-1559 burns), scalability improvements, and a mature staking ecosystem continuously enhance ETH’s store of value, supporting upward price movement.