# StableFX Fees Methodology

## 1. Overview

Fees for StableFX are measured as the total transaction fees paid by users executing foreign exchange trades on Circle's StableFX product. These fees are collected from both the maker and taker sides of every settled trade. This metric is utilized to quantify the economic value and transaction volume generated by Circle's institutional FX trading infrastructure on Arc.

## 2. Data sources

- **Blockchain events**: `TradeStatusChanged`, `TakerRefunded`, and `MakerRefunded` events, alongside `recordTrade` and `authorizeTrade` function calls from `FxEscrow` contracts, covering Arc
- **External data**: End-of-day price feeds and asset metadata for token decimal normalization and USD conversion

## 3. Step-by-step calculation

### Component A: Trade settlement and refund filtering

- **Purpose**: Identify successfully settled StableFX trades and exclude refunded or system transactions.
- **Logic**: Trade details are extracted from `recordTrade` and `authorizeTrade` function calls from `FxEscrow` contracts. These trades are matched with `TradeStatusChanged` events where the status is updated to settled. Trades that have corresponding `TakerRefunded` or `MakerRefunded` events are excluded. Transactions involving system emitter addresses are also filtered out.
- **Key fields**: `trade_id`, `taker_address`, `maker_address`, `base_token_address`, `quote_token_address`, `base_amount`, `quote_amount`, `taker_fee`, `maker_fee`

### Component B: Fee extraction and decimal normalization

- **Purpose**: Extract maker and taker fees and normalize them based on asset decimals.
- **Logic**: Fees are charged to both sides of every settled trade, with each participant paying in the asset they deliver. Taker fees and maker fees are extracted from the settled trade records. These raw fee amounts are normalized by the decimal precision of their respective assets using asset metadata.
- **Key fields**: `taker_fee`, `maker_fee`, `taker_delivered_token_address`, `maker_delivered_token_address`

### Component C: USD conversion and aggregation

- **Purpose**: Convert normalized fee amounts to USD and aggregate them daily.
- **Logic**: Normalized taker and maker fees are converted to USD using end-of-day price feeds for each respective fee asset. The USD values of both fee legs are summed to represent the total fees collected per trade. These values are then aggregated to a daily granularity using UTC day boundaries.
- **Key fields**: `fees`, `timestamp`

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

Total value users pay to use a protocol (gross fees, user-paid fees).

Fees

Exchanges (DEX)

Users deposit funds into Circle account and receive USDC or EUROC at a 1:1 rate.

Circle is a financial technology company that is the principal architect of USDC and EUROC - full-reserve fiat stablecoins that bring US dollar and euro liquidity on-chain.

Circle is a private company registered in the US. Circle's investors include Goldman Sachs, Baidu, and IDG Capital etc.

StableFX

Fees

Fees

Chain breakdown