According to CryptoPotato, Bitcoin’s developer community has been discussing the potential of OP_CAT, a proposed soft fork change, as a significant evolution for Bitcoin. However, Robin Linus, the creator of BitVM, has expressed concerns about the change, publishing an article to address perceived misconceptions about OP_CAT. Linus argues that OP_CAT could introduce risks to Bitcoin that are often downplayed by its proponents. He emphasizes the need for a fact-based, rational analysis of the change rather than a one-sided promotion. One of his main concerns is that OP_CAT could alter the incentives for Bitcoin miners and affect the security of the entire network. Linus points out that the design space for OP_CAT-based DeFi applications on Bitcoin is largely unexplored, making it difficult to predict all potential innovations and their impact on maximal extractable value (MEV). OP_CAT, an old Bitcoin opcode initially created to concatenate two pieces of data, was removed by Satoshi Nakamoto in 2010 due to security concerns. It was reintroduced in 2023 through BIP 347 to handle more complex data structures like Merkle trees, enhancing its functionality. Supporters of OP_CAT argue that the change involves only 10 lines of new code and reintroduces old technology, thus minimizing attack vectors. However, Linus counters that the simplicity of the code does not guarantee its safety, as it is impossible to predict all consequences of activating OP_CAT. One of the most touted benefits of OP_CAT is its ability to introduce covenants, or conditional payments, to Bitcoin. Linus argues that OP_CAT-based covenants would be inefficient in terms of block space and transaction fees, suggesting that other opcode proposals would be better suited for this purpose. Bob Bodily, co-founder and CEO of Bioniq and a supporter of OP_CAT, agrees with Linus on the inefficiency of OP_CAT-based covenants but believes that OP_CAT offers more than just covenants. Bodily argues that OP_CAT is a lower-level primitive that could enhance various functionalities, including Linus’s BitVM model. He believes that OP_CAT would make the BitVM model more efficient, cheaper, and more flexible. Despite Linus’s reservations, Bodily sees OP_CAT as a valuable addition to Bitcoin’s ecosystem. The debate over OP_CAT highlights the ongoing discussions within the Bitcoin community about the best path forward for the cryptocurrency’s development and security.