Fusaka launched on December 3, 2025, marking Ethereum's second major hard fork of 2025 after Pectra. This is a significant step forward in how the network handles data, supports Layer 2 growth, and prepares for wider user adoption.
What’s the Fusaka upgrade?
Ethereum has activated the Fusaka (short for Fulu-Osaka) hard fork, a coordinated update on how the mainnet collects and verifies data from layer-2 networks involving two components:
- Osaka (Execution layer): Adjusts how transactions are processed.
- Fulu (Consensus layer): Improves how validators reach agreement on the chain’s state.
The core feature is the introduction of PeerDAS (Peer Data Availability Sampling), a system that allows nodes to verify data by sampling pieces rather than downloading entire data sets.This dramatically reduces validator load and improves how Ethereum handles rollup data.
See launch video on X here.
Why is PeerDAS important?
PeerDAS is intended to make Ethereum far more efficient.This upgrade enables:
- Up to 8x more data throughput (under optimal conditions)
- Reduced strain on the main chain
- More scalable and cost-efficient operations for Layer 2 networks such as Arbitrum, Base, and Optimism
With this update, Ethereum’s capacity to handle higher transaction volumes without increasing fees is enhanced.While actual gains will depend on network demand and rollup adoption, PeerDAS meaningfully improves the infrastructure needed for long-term scaling.
Where does the Fusaka upgrade fit in Ethereum’s long-term roadmap?
Understanding Fusaka’s impact becomes clearer when viewed within Ethereum’s broader timeline of major upgrades:
- The Merge (2022): Shifted the network from energy intensive proof-of-work to proof-of-stake.
- Shanghai (2023): Enabled validators to withdraw staked ETH, improving liquidity and validator participation.
- Dencun (March 2024): Introduced blobs, temporary data packets. This slashed L2 fees by 90–95%.
- Pectra (May 2025): Expanded blob capacity and improved validator flexibility.
- Fusaka (December 2025): Dramatically increases data availability through PeerDAS and prepares the network for 100,000+ TPS in future phases.
Will Fusaka Impact ETH Price?
Technical upgrades strengthen fundamentals, but market performance often diverges from protocol improvements.
ETH trading above $3,000 around the upgrade reflects wider macro conditions, institutional positioning, and overall market sentiment, not the upgrade alone.
Traders should view Fusaka as a structural improvement, not a short-term price catalyst.
Analysts are talking about based rollups. What does this mean?
Based rollups are a design in which Ethereum validators, not the rollup operators, handle transaction sequencing. Currently, most Layer 2 networks retain revenue from fees and MEV extraction. With Based Rollups, some of this value could flow back through Ethereum’s validator ecosystem.
Fusaka provides the foundation for this model, but actual adoption depends on individual L2 teams. Market observers expect this narrative to grow in importance over the next several months.
What is the under-discussed feature in this upgrade?
EIP-7951 introduces native support for secp256r1 signatures, enabling passkey-based authentication. This allows applications to use secure hardware in smartphones for authentication, offering:
- A simplified login experience
- Reduced reliance on seed phrases
- Greater accessibility for new users
This feature may help onboard a wider audience as wallets and applications integrate the capability.
What should traders monitor after the Fusaka rollout?
While the upgrade improves Ethereum’s long-term architecture, short-term market activity remains influenced by sentiment. Key areas worth observing include:
- Price zones: Market watchers are evaluating reactions near $2,700 (support) and $2,900–$3,000 (resistance).
- ETH/BTC performance: Indicates relative strength against Bitcoin after the upgrade.
- Layer 2 transaction costs: Early signs of PeerDAS efficiency gains.
- Network metrics: Throughput, blob usage, and validator behavior as demand increases.
- Ecosystem adoption: Uptake of passkeys and rollup-related improvements.
These signals help contextualize the upgrade’s impact without assuming or predicting market outcomes.
Fusaka is a meaningful architectural step for Ethereum, a foundational upgrade that strengthens the network for long-term scaling and adoption.
For traders, the value lies in tracking L2 activity, validator behavior, and ecosystem adoption, rather than expecting immediate market reactions.
Additional resources:
