# Robinhood Chain Expenses Methodology

## 1. Overview

Expenses is defined as the total cost incurred by Robinhood Chain to operate its business. Included in this metric are L1 settlement fees paid to post batches to Ethereum, as well as Arbitrum Expansion Program (AEP) license fees paid to the Arbitrum Foundation. Token incentives are also included but are currently set to zero. This metric is utilized to analyze the operational efficiency and profitability of the rollup infrastructure.

## 2. Data sources

- **Blockchain events**: Transaction data and native asset flows, covering Ethereum and Robinhood Chain
- **External data**: End-of-day price feeds for native gas assets

## 3. Step-by-step calculation

### Component A: L1 settlement fee calculation

- **Purpose**: To calculate the gas costs incurred on Ethereum for posting rollup batches.
- **Logic**: Transactions sent by the sequencer address (`0xdaa526086787d9debe1d7f3ffdb1fe50cf8687f4`) on Ethereum are filtered. The gas fees are calculated by multiplying the gas used by the effective gas price, and adding the product of blob gas used and blob gas price. The resulting amounts are normalized by decimal precision to represent the total L1 settlement cost in native Ether.
- **Key fields**: `block_timestamp`, `gas_price`, `blob_gas_price`, `gas_used`, `blob_gas_used`

### Component B: Arbitrum Expansion Program (AEP) license fee calculation

- **Purpose**: To calculate the license fees owed to the Arbitrum Foundation.
- **Logic**: Native asset flows on Robinhood Chain are filtered for specific fee accounts (RewardDistributors representing network and infrastructure fee accounts). Inflows categorized as fee inflows and refund outflows are aggregated to determine the net fee inflow. A predefined AEP license fee rate is applied to this net inflow to calculate the license fee expense. The resulting amounts are normalized by decimal precision.
- **Key fields**: `block_timestamp`, `value`, `account_address`, `category`

### Component C: Token incentives tracking

- **Purpose**: To track token incentives distributed to users.
- **Logic**: Token incentives for Robinhood Chain are set to a constant value of zero.
- **Key fields**: None

### Component D: USD conversion and aggregation

- **Purpose**: To convert all expense components to USD and aggregate them.
- **Logic**: The L1 settlement fees and AEP license fees are summed to calculate the total cost of revenue. This cost of revenue is combined with token incentives (which are zero) to determine total expenses. Daily expense values are converted to USD using end-of-day price feeds for the native gas asset. Daily granularity is maintained with UTC day boundaries.
- **Key fields**: `block_timestamp`, `expenses`

*This methodology was automatically generated by Token Terminal's methodology analyzer.*

Total project operating and incentive expenses.

Expenses

Robinhood Chain

Expenses

Expenses

Chain breakdown