How will Ethereum's 'Shanghai' upgrade affect the second-largest cryptocurrency?
As a keen observer of the cryptocurrency market, I'm eager to understand the potential implications of Ethereum's impending 'Shanghai' upgrade. Could you elaborate on how this upgrade, which promises to introduce various improvements and innovations, is likely to impact the second-largest cryptocurrency? Will it enhance Ethereum's scalability, security, or sustainability? Will it bring about significant changes in transaction speeds, fees, or user experience? Additionally, how might it reshape the competitive landscape in the crypto world, and what opportunities or challenges might it present for investors and developers alike?