The project that once taught us the first lessons of blockchain is now struggling to survive.

The Incident Timeline

On the evening of April 15, the price of ZKsync’s token ZK experienced an abnormal drop, falling more than 14% within 24 hours and briefly dipping below $0.04. After the incident, exchanges like Bithumb suspended ZK deposits and withdrawals.

According to on-chain data, the actual attack took place at 8:00 PM (UTC+8) on April 13. The attackers accessed an airdrop distribution contract’s admin account and called the sweepUnclaimed() function in the contract, minting around 111 million unclaimed airdrop tokens. The attackers then began selling around 66 million of these tokens and transferring them across chains. By the time the incident was exposed on April 15, around 44.68 million tokens were still remaining in the attacker’s address.

At 9:00 PM on April 15, the community first disclosed the abnormal minting and selling behavior on social media platforms. ZKsync’s official team later responded, confirming that the issue was due to the leakage of admin keys for three airdrop distribution contracts, which caused the abnormal minting of tokens. The official statement clarified that the incident only affected the airdrop contract and did not impact the ZKsync protocol itself, the ZK token main contract, governance contracts, or other token distribution plans. The circulating supply of the token increased by approximately 0.45%, with a total value of about $5 million.

On the night of the incident, the ZKsync team coordinated with exchanges to attempt to freeze the related funds and called on the attackers to return the tokens to avoid legal consequences. The official team emphasized that the attack vector could no longer be exploited, and the rest of the system remained unaffected.

After the incident, the ZK token price briefly rebounded but has not yet returned to pre-incident levels. As of now, the investigation is still ongoing, and the project team has promised to release further details.

From Kings to Fallen?

Once considered the “Four Kings” of Ethereum Layer 2—ZKsync, Arbitrum, Optimism, and Starknet—their trajectories have now diverged significantly. It’s worth noting that many of my peers first encountered on-chain operations through airdrops from these projects, learning basic concepts such as wallets, interactions, and gas fees. These projects not only carried out the technical practices of Ethereum scaling but also served as the entry point for many into the crypto world.

ZKsync and Starknet both follow the ZK Rollup approach and were once seen as technical representatives of this solution, emphasizing higher security and data validity. ZKsync promoted its zkEVM, compatible with Ethereum, as a selling point, aiming to reuse Ethereum’s ecosystem tools to lower development barriers. In contrast, Starknet stuck to its proprietary Cairo language system, offering higher performance potential but limiting its ecosystem expansion. On the other hand, Arbitrum and Optimism adopted the more mature OP Rollup solution, leveraging optimistic proofs to settle transactions. This allowed them to penetrate the market faster in terms of developer tools and compatibility.

In terms of ecosystem development, Arbitrum is undoubtedly the strongest project at present. Not only has it seen native DeFi projects like GMX take root, but its overall application layer distribution is also much richer. Optimism, meanwhile, is more focused on governance and architectural expansion. With the launch of the OP Stack and the creation of the Base mainnet in collaboration with Coinbase, it has begun to construct a “modular consortium chain” framework. ZKsync’s ecosystem, on the other hand, has mostly stagnated after the airdrop, with multiple projects fleeing shortly after, severely damaging user and developer confidence. Starknet has always had a slower development pace, and its ecosystem expansion is relatively lagging.

In terms of user activity, Arbitrum has consistently led, far surpassing the other projects in both on-chain active addresses and transaction volume, with Optimism following closely behind. ZKsync saw a peak in activity during the airdrop phase but has quickly fallen off, with daily active users now at a low point. Starknet’s data has remained stable but has shown little growth, struggling to break through.

The on-chain locked value also clearly reflects the differences between these projects. According to DefiLlama, Arbitrum remains at the top of the L2 TVL chart with $2.1 billion, demonstrating a certain level of economic self-sustainability. Optimism, with the expansion potential of OP Stack, also maintains high expectations. ZKsync’s revenue has long been sluggish, with its TVL only seeing fluctuations at specific events and lacking long-term growth momentum. Starknet faces a similar issue, with both its revenue and locked value being small.

From the data on capital bridging, the differences in ecosystem activity are also very evident. According to Dune, Arbitrum’s official cross-chain bridge has accumulated over 4 million ETH in bridged funds, firmly holding the top position among all Layer 2 projects. ZKsync follows closely with about 3.7 million ETH, which, while not a low figure, reflects a significant decline in activity. In the past seven days, only 14 users have used the ZKsync official bridge, and the total bridged amount was just 5 ETH, almost at a standstill. In contrast, Optimism and Starknet’s total bridging volumes have not been high, with neither surpassing 1 million ETH.

It is worth noting that although Arbitrum has performed steadily in terms of its on-chain ecosystem, with continued user activity and project implementation, its token price trajectory has not been ideal. Since its peak last year at around $2.40, the price of ARB has retraced by over 88%, but its current market capitalization remains above $1.3 billion. This contrast may be closely related to the continuous release of its circulating supply. Since the token’s launch, Arbitrum has undergone several large unlocks, leading to sustained market sell pressure, which has weighed down the price.

The former “Four Kings” of Layer 2 once represented the future direction of Ethereum scaling and served as the first entry point for countless users. However, after experiencing technical deployment, airdrop battles, security incidents, and project fragmentation, the current Layer 2 landscape no longer enjoys its former spotlight.

The once repeatedly emphasized qualities of “high performance, low cost, and strong security” now seem to be losing their appeal. How much longer can the narratives centered on Layer 2 as an entry point hold? In a time when both capital and attention are flowing elsewhere, is Layer 2 really the bridge to large-scale applications, or is it merely a temporary transitional solution? Will the projects once highly anticipated end up stalling in the middle of their technical evolution?

Disclaimer:

1. This article is reprinted from [ChainCatcher], with the copyright belonging to the original author [Airdrop Insulator Scof, ChainCatcher]. If you have any objections to the reprint, please contact the Gate Learn team, who will process it according to the relevant procedures.

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