If the ZK narrative fully explodes, it will ignite at least three fires: Privacy → Scaling → General. 1. ZK-Privacy. ZK-Privacy achieves transaction anonymity through zero-knowledge proofs. Its core logic is to hide details such as the sender, receiver, and amount in a transaction. This not only responds to long-standing concerns about privacy protection but also demonstrates strong demand in scenarios such as enhancing Know Your Customer (KYC) compliance and protecting data for large AI model training. The recent resurgence of Zcash is driven by both institutional interest and endorsement by prominent investors who see it as "an insurance policy for Bitcoin." More importantly, Zcash's optional privacy features strike a balance between compliance and anonymity, making it a core element of the current privacy narrative. Key targets for observation: $ZEC $XMR $DASH $XVG $ARRR 2. ZK-Scaling (Extension) ZK-Scaling, primarily based on ZK-Rollup technology, provides a high-throughput, low-cost Layer 2 scaling solution for blockchains like Ethereum. In the past two cycles, ZK's market hype stemmed from its "end-game application" in Layer 2 scenarios. However, the challenge now is that general Layer 2 infrastructure is already quite sufficient, and whether the ecosystem can keep pace is the decisive factor. Starknet has benefited from the surge in the privacy sector this round. Its founder, Eli Ben-Sasson, was a core member of the Zcash team in his early years. As the privacy craze wanes, it remains to be seen whether ZK scaling can take over as the second wave of the main upward trend. Key targets for observation: $STRK $ZK $LRC $IMX 3. ZK-General The goal of ZK-General is to generalize zero-knowledge proof technology, enabling its embedding in a wider range of verticals, including cross-chain bridges, private smart contracts, identity verification, and AI reasoning. The core focus is to reduce the cost of use and promote the large-scale commercialization of ZK technology. Currently, projects such as Mina, Aleo, Boundless, and Succinct are actively developing in this direction. Logically, generalization should be the first wave of ZK technology's explosion, followed by the logical extension of scalability and privacy. However, the reality is quite the opposite—institutional power and policy direction appear to have significantly reshaped the pace of technology dissemination. Key projects to watch: $ZKC $PROVE $MINA $ALEO $AZTEC $VFY $IRON Additionally, several projects exist at the intersection of privacy and scalability. Railgun is committed to building a privacy layer on public chains like Ethereum, providing a complete privacy solution through application protocols; Horizen is positioned as a platform supporting the development of privacy-focused applications and promoting the large-scale adoption of "ZK as a Service." These projects have risen in tandem with Zcash, both due to their real TVL and usage data at the application layer and due to their smaller market capitalizations and limited name recognition, resulting in greater price resilience.