In fact, $SUI and Aptos were initially closely related ecosystems, but due to differences, they eventually went their separate ways. Now they are in fierce competition for leadership. The two projects are engaged in comprehensive competition in areas such as consensus algorithms, developer community building, and commercial resources. In terms of ecological development direction, they have chosen completely different paths. $SUI chose a realistic route, focusing on incubating DeFi and Meme projects, while Aptos chose an idealistic route, laying out the Bitcoin ecosystem. Aptos's Bitcoin ecological strategy is a 'dual approach.' On one hand, it collaborates with the mature Bitcoin Layer 2 solution Stacks to quickly enter the market using its technology and user base; on the other hand, it deeply collaborates with the emerging B² Network to gain growth dividends from the new paradigm of Bitcoin L2. Today, we will discuss the Echo Protocol, which is a key piece in the grand chess game between Aptos and Bitcoin. Why is Arthur Hayes so optimistic about the Echo Protocol? The answer may lie in one of his bold predictions. Hayes believes that during the current market cycle, Aptos's performance may surpass Solana and is expected to become the second largest Layer 1 public chain after Ethereum within one to three years. Echo Protocol is undoubtedly the perfect link connecting the two areas he is optimistic about: Aptos and Bitcoin. Echo is not just a simple BTC bridging tool, but a comprehensive protocol that integrates BTC bridging, liquid staking, Restaking, and yield optimization. Most importantly, Echo's appeal lies in its real yield model. It provides users with a 10% annualized real yield based on a staking value calculation of $BTC USD through cooperation with APT, and distributes it monthly in the form of APT tokens. This model not only creates stable cash flow for BTC holders but also brings a large number of high-quality assets into the Aptos ecosystem, achieving a win-win situation.