Ethereum’s Fusaka Upgrade Paves Way for $1 Trillion Layer 2 Market in 6 Years

Ethereum’s Fusaka upgrade, designed to enhance scalability and node efficiency, is set to activate on the mainnet on December 3, 2025, following a systematic testnet rollout beginning on October 1, 2025, on the Holesky networktitle1^[1]. The upgrade will implement approximately 11-12 Ethereum Improvement Proposals (EIPs), focusing on backend protocol enhancements rather than user-facing features. Key among these is the phased expansion of blob capacity through Blob Parameter Only (BPO) forks, which will incrementally increase blob limits from 6/9 to 14/21 target/max within two weeks of the mainnet launchtitle1^[1]. This expansion is intended to significantly boost data availability for Layer 2 rollups, reducing bandwidth and storage demands for nodestitle2^[2].

The Fusaka upgrade prioritizes infrastructure improvements, including the implementation of Peer Data Availability Sampling (PeerDAS) via EIP-7594. This technique allows validator nodes to verify data by sampling small portions of blobs rather than downloading entire datasets, enhancing scalability while maintaining network securitytitle1^[1]. Complementing this, the gas limit for blocks is set to increase from 30 million to 150 million units, a 400% theoretical throughput boost, with further discussions on potential expansions to 2,000 transactions per second over two yearstitle2^[2]. These changes aim to address growing transaction volumes while preserving decentralization.

A structured four-phase testnet deployment precedes the mainnet rollout. Holesky, Sepolia, and Hoodi testnets will activate on October 1, October 14, and October 28, 2025, respectively, each undergoing the full BPO fork sequence to validate the blob capacity expansion mechanismtitle1^[1]. The first BPO fork, targeting a 10/15 blob limit, is scheduled for December 17, 2025, followed by a second fork on January 7, 2026, to reach the final 14/21 limittitle1^[1]. This automated approach ensures flexible scaling without requiring full network upgrades.

Security measures for the upgrade include a four-week auditing contest with up to $2 million in rewards for identifying critical vulnerabilitiestitle2^[2]. Node operators face staggered deadlines from September 25, 2025 (Holesky) to November 3, 2025 (mainnet), allowing sufficient preparation time while minimizing disruptionstitle1^[1]. The Ethereum Foundation emphasizes that these measures reinforce network resilience against scalability bottlenecks and attacks.

The upgrade addresses mounting pressure for Ethereum’s base layer improvements, particularly amid criticism of Layer 2 fragmentation. By increasing blob capacity and optimizing data verification, Fusaka supports higher transaction throughput without compromising decentralizationtitle2^[2]. Analysts note that these changes align with broader institutional interest in Ethereum infrastructure, including predictions that Layer 2 networks could reach a $1 trillion market capitalization within six yearstitle1^[1].

Fusaka’s implementation also includes bounded base fees for blob transactions via EIP-7918, providing predictable costs for data-heavy applicationstitle1^[1]. Additionally, the upgrade defers more complex changes, such as the EVM Object Format (EOF) redesign, to the subsequent Glamsterdam upgrade in 2026, ensuring a focused rollout of essential infrastructure enhancementstitle2^[2].

The phased blob expansion and PeerDAS implementation are expected to lower barriers for smaller node operators, potentially increasing network decentralizationtitle1^[1]. Combined with gas limit increases, these features position Ethereum to handle elevated transaction volumes while maintaining security guarantees. The upgrade’s success could further unify fragmented multichain ecosystems, as seen in initiatives like the Open Intents Framework, which aims to address cross-chain interoperability challengestitle1^[1].