Read 2026-11-14 · four exchange APIs · rebuilt daily

Layer 2 fees explained by execution and settlement data

Layer 2 fees explained: Execution costs versus settlement publication

Rollups process transactions off-chain on a single sequencer, calculate state updates, and publish the compressed transaction payload back to the Layer 1 base chain. Because execution occurs off-chain, the computing cost per transaction is low. However, the rollup must pay Layer 1 gas to store its data payload permanently on the settlement chain.

The total cost paid by an end user to execute a transaction on a Layer 2 network follows a two-part equation:

Total L2 Fee = (L2 Gas Used L2 Gas Price) + (L1 Data Gas Used L1 Base Fee)

The first term covers local execution on the rollup virtual machine, including memory allocation, state reads, and storage writes. The second term covers the overhead incurred when the sequencer posts the transaction batch to Layer 1. On networks experiencing mainnet congestion, Layer 1 data publication can represent more than 90 percent of the total fee charged for a Layer 2 transaction.

How blob data altered the settlement cost structure

Before consensus upgrades introduced dedicated data blobs, rollups published transaction batches directly inside Layer 1 execution calldata. Calldata is permanently accessible to all smart contracts on the base layer and competes directly with regular L1 transfers for execution gas. This mechanism tied Layer 2 transaction fees directly to Layer 1 execution gas price spikes.

Data blobs isolate rollup batch storage into dedicated data blocks attached to consensus layer payloads. Blobs do not compete with L1 smart contract execution gas. Instead, blob space operates under an independent fee market calibrated specifically for temporary data availability.

The cost of publishing rollup data using dedicated blobs is determined by a separate pricing mechanism:

Blob Fee = Blob Gas Used * Blob Base Fee

Because consensus nodes prune blob data after a temporary storage window, the per-byte cost of blob space is significantly lower than permanent calldata storage. When total blob utilization remains below target capacity, the blob base fee remains at its floor, driving the Layer 1 settlement component of Layer 2 fees down close to zero.

Why canonical bridges enforce a seven-day withdrawal delay

Moving assets between Layer 1 and Layer 2 relies on smart contract bridges. Depositing funds from Layer 1 to Layer 2 completes within minutes because the Layer 2 sequencer registers the L1 deposit event as soon as the base layer reaches finality. Returning assets from Layer 2 back to Layer 1 follows a different timeline on optimistic rollups.

Optimistic rollups assume state assertions submitted by the sequencer are correct without executing every transaction on Layer 1 upfront. To prevent invalid state transitions or unauthorized withdrawals, the canonical bridge contract enforces a mandatory 7-day challenge window before releasing assets on Layer 1.

During this 7-day challenge period, network verifiers monitor published transaction batches. If a verifier detects an incorrect state root, it submits a fraud proof to the Layer 1 bridge contract. If Layer 1 re-execution validates the fraud proof, the invalid state update is discarded and the sequencer's staked collateral is slashed. The 7-day delay ensures verifiers have sufficient time to detect faults, compute proofs, and broadcast transactions even during periods of extreme L1 network congestion.

Centralized exchange fee schedules and perpetual holding costs

While Layer 2 network fees pay for transaction execution and batch data settlement, holding positions on centralized derivative exchanges incurs venue-specific execution fees and funding rates. Exchange execution fees apply directly to the nominal position value upon order execution.

The table below details published futures maker and taker fee schedules across major trading venues:

For market orders, fee tiers vary significantly across venues. Entering and exiting a position on MEXC costs 0.0002 per trade side in futures taker fees, whereas Bybit charges 0.00055 per trade side. On a nominal position size of $100,000, round-trip taker fees equal $40 on MEXC compared to $110 on Bybit.

Perpetual futures positions held open across settlement timestamps incur funding fee adjustments every 8 hours. The table below lists active 8-hour funding rates for ETH and BTC across the same venues:

A trader holding a long ETH position on Bitget earns a funding credit of 0.0006% per 8 hours due to the negative rate. The same long ETH position held on Bybit incurs a funding charge of 0.0100% per 8 hours. Over 24 hours (three intervals), the funding fee spread between Bitget and Bybit on a long ETH position amounts to 0.0318% of nominal position size.

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