Ethereum Fusaka Upgrade: Scaling Infrastructure Through Data Efficiency

On 3 December 2025, Ethereum activated the Fusaka upgrade, a structural shift in how the network manages rollup data. Through PeerDAS, which is a sampling mechanism that eliminates the requirement for nodes to download complete datasets, Fusaka increases blob capacity — the amount of data attached to blockchain blocks — up to 8x while reducing burdens on validators (nodes). The result? More predictable fee environments for institutional rollup operators. This is important as major asset managers like BlackRock, Franklin Templeton, and Amundi have begun deploying tokenised products at scale. Fusaka shifts the risk profile from “can it scale?” to “will adoption follow the infrastructure upgrade?” Fusaka demonstrates scalability while preserving the ideals of decentralisation. Now the only question is whether deployment will match Ethereum’s expanded capacity.

Fusaka follows seven months after the Pectra upgrade, which was activated on 7 May 2025 and refined staking operations and improved wallet usability. Pectra focused on user-facing comfort. Fusaka, by contrast, tackles a deeper challenge: Ethereum’s ability to handle vast amounts of data generated by Layer 2 rollups such as Base, Arbitrum and Optimism.

Rollups are secondary networks that process transactions offchain and publish batches of data back to Ethereum for verification. They now handle the majority of Ethereum’s transaction load.

To understand this shift, it helps to look at recent numbers.

Between December 2024 and December 2025, Ethereum averaged 21 UOPS (user operations per second), while rollups processed 3,780 UOPS, representing a scaling factor of more than 155 times the base layer. Leading rollups like Lighter, Base, Arbitrum One and Starknet consistently exceeded Ethereum’s throughput by wide margins. Rollups now handle more than 70% of all user activity, while Ethereum remained the settlement and data availability layer.

These figures show why Ethereum’s ability to scale data throughput now matters far more than raw execution capacity.

Ethereum’s long-term roadmap divides this era of development into three phases known as the Surge, the Verge and the Purge. Fusaka belongs to the Surge, which is the phase dedicated to increasing data throughput. Its activation signals that Ethereum is ready to support rollups not merely as additions to the Mainnet, but as the central engines of the ecosystem.

At the heart of Fusaka lies PeerDAS (Peer Data Availability Sampling), a system that allows nodes to verify the availability of rollup data without downloading it in full. Before Fusaka, every node was required to download all rollup data published to the base chain. This approach was simple, but it placed a heavy bandwidth and storage burden on validators and prevented blob capacity from scaling meaningfully.

PeerDAS changes the model entirely. Instead of downloading everything, each node stores a small, randomly assigned portion of the data. Nodes verify dataset availability by requesting samples from other nodes across the network. Random sampling makes unavailable data detection statistically certain.

This system is supported by advanced erasure coding — a technique that breaks large amounts of data into many redundant fragments. Even with missing fragments, the network can still reconstruct the complete dataset from the remaining pieces. A useful analogy is a puzzle where you can still recreate the full picture even if a few pieces go missing because extra backup pieces exist.

The result is a more efficient and sustainable foundation for rollups. Ethereum can now host significantly more rollup data without increasing the burden on its participants.

Fusaka also reshaped how Ethereum expands its data capacity. Rollups publish their transaction batches into temporary data packets called blobs. Before Fusaka, any increase in blob capacity required waiting for a full network upgrade, which often took a year or more.

Fusaka introduced Blob Parameter Only forks — configuration updates that adjust parameters like maximum number of blobs per block without modifying deeper protocol rules. This allows capacity increases in response to real demand rather than fixed upgrade cycles.Returning Stability to Blob Pricing

One of the less visible but economically important changes in Fusaka addresses blob pricing. Previously, fees fell to trivial levels during quiet periods or experienced distortions from execution gas spikes.

Fusaka corrected this by anchoring blob fees to a minimum level tied to execution gas costs. This ensures that fees reflect genuine network demand and prevents the market from collapsing into meaningless values. For institutions and rollup operators, this results in a far more predictable environment for planning and settlement.

A series of smaller but crucial refinements were also introduced. Ethereum now limits gas consumption in a single transaction, preventing any one operation from monopolising a block. The ModExp repricing function, often used in cryptographic operations, has been simplified so that cryptographic costs matches the actual computing power it uses, which prevents attackers from slowing down the network with unusually heavy operations. A maximum block size has also been formally defined to ensure safe network propagation.

These safeguards ensure that as Ethereum becomes more capable of handling greater data loads while stability and security remain intact. This is particularly important as rollup activity scales and transaction complexity increases across instituional use cases.

Validators now benefit from deterministic proposer lookahead. This means that the network can predict which validator will propose each block in advance.  This predictability improves settlement reliability, enables advanced confirmation systems, and eliminates schedule manipulation risks. For institutional settlement workflows, this removes some of the integration complexity and translates into greater settlement assurance.

One of the most user-facing improvements is the introduction of native support for the  , the cryptographic standard used in   and many enterprise security devices. With this support, wallets can integrate passkeys, biometrics, and hardware-backed authentication directly. It brings Ethereum’s user experience closer to modern digital banking, reducing friction for both individuals and institutions.

Fusaka underwent extensive testing across multiple public testnets, including Holesky, Sepolia and Hoodi. Each phase simulated adverse conditions such as network splits, slow validators and bandwidth-constrained nodes. Client teams collaborated closely and the Ethereum Foundation encouraged scrutiny through substantial bug bounty incentives.

Since activation, early data shows healthy validator participation and smooth block propagation. The absence of disruptions is perhaps the clearest proof of the upgrade’s maturity.

Fusaka activates at a time when Ethereum is experiencing its strongest wave of institutional engagement. Throughout 2024 and 2025, major financial institutions began using Ethereum and Ethereum-compatible infrastructure for tokenised funds, collateral systems, and digital markets. The most significant development came in November 2025, when Amundi, Europe’s largest asset manager, launched a tokenised share class of its money market fund directly on public Ethereum. The fund operates through a hybrid model where a tokenised share class is recorded onchain, supported by CACEIS custody and stablecoin-enabled settlement. This deployment marked the first time a top-tier global asset manager brought a regulated investment product to Ethereum at full operational scale rather than as a pilot.

This movement builds on earlier expansion across the sector. BlackRock’s BUIDL fund, launched in March 2024, exceeded 1 billion dollars in assets under management by early 2025 and became eligible as collateral at several trading venues. Franklin Templeton continued expanding its Benji tokenisation platform in 2025 across Ethereum, Arbitrum, Avalanche, Aptos and Base, alongside new integrations with the Canton Network. Together, these developments pushed Ethereum to the top of the tokenised real-world asset market with more than $11 billion in tokenised value, significantly ahead of other chains.

Regulation has advanced in parallel. MiCA’s implementation across the European Union in 2025 created a unified framework for stablecoins, asset-referenced tokens and tokenised investment products. This clarity helped enable large-scale deployments such as Amundi’s Ethereum product launch and strengthened the outlook for additional regulated issuers. In Switzerland, Boerse Stuttgart Group received approval in early 2025 to operate a blockchain-based trading and settlement system, further signalling that European market infrastructure is preparing for tokenised assets anchored to EVM-compatible rails.

Historical pricing patterns following major upgrades suggest measured medium-term responses rather than immediate rallies. During the Merge in 2022, Ethereum saw an initial decline followed by a 75% recovery over the next six months as staking adoption accelerated. After the Pectra upgrade in May 2025, Ethereum rose by about 40% in the week after activation and regained key resistance levels that had held for months. Whether Fusaka produces a similar price response in the months ahead will depend on the speed at which rollup fees fall and institutional tokenisation volumes expand. What is clear is that the upgrade strengthens the foundation at a time when institutional usage is no longer theoretical but increasingly operational.

Fusaka is now live and already reshaping Ethereum’s infrastructure. It introduces a more efficient data model, stabilises core economic mechanisms, strengthens the network’s security, and prepares the foundation for future upgrades such as Glamsterdam, which aims to introduce parallel execution and shorter slot times. Shorter slot times mean that blocks will be created more frequently, reducing the time users wait for their transactions to be included and increasing the speed at which the network finalises activity.

For institutions evaluating Ethereum’s viability as a long-term settlement platform, Fusaka provides a clear signal. Ethereum is scaling with precision rather than hope. It is entering a phase where its architecture is not merely theoretical but deployed, tested and trusted at global scale.

With Fusaka, Ethereum begins its next decade not as a promising experiment but as a maturing, resilient and strategically evolving financial infrastructure. The upgrade demonstrates technical scability while preserving decentralisation. The remaining questions centre on whether developers, users, and most importantly institutions deploy applications and capital at the pace Ethereum’s infrastructure now supports.

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