Ethereum exchange reserves have plummeted to a 5-year low, driven by a massive 110,000 ETH withdrawal from Coinbase. This is seen as a positive sign for Ethereum, as it suggests that investors are increasingly confident in the network and willing to hold their ETH outside of exchanges. This is also positive for Ethereum from a security standpoint, as it makes it more difficult for hackers to steal large amounts of ETH. Overall, the massive ETH withdrawal from Coinbase is a bullish signal for Ethereum and its future.