# Bitcoin Active addresses (monthly) Methodology

## 1. Overview

Bitcoin monthly active addresses measures the number of unique Bitcoin addresses that sent at least one transaction within a rolling 30-day window. This metric answers the question "How many distinct Bitcoin addresses were actively spending Bitcoin in the past 30 days?" For Bitcoin, active addresses are equivalent to active users since each address represents a potential user sending transactions. The calculation uses Bitcoin's UTXO (Unspent Transaction Output) model to resolve transaction inputs back to their controlling addresses, then applies HyperLogLog sketches for efficient distinct counting over rolling monthly windows.

## 2. Data sources

The calculation relies on these raw Bitcoin blockchain data sources:

- **Bitcoin transaction records**: Complete Bitcoin blockchain transaction data containing transaction hashes, block timestamps, inputs, and outputs
- **Bitcoin transaction outputs**: Transaction output data including `scriptPubKey` fields that contain Bitcoin addresses and output indices
- **Bitcoin transaction inputs**: Transaction input data referencing previous transaction outputs via transaction hash and output index (`vout`) fields
- **UTXO references**: The linkage between transaction inputs and the previous transaction outputs they spend, enabling address resolution in Bitcoin's UTXO model

## 3. Step-by-step calculation

### Component A: Bitcoin address resolution
- **Purpose**: Creates a lookup table mapping Bitcoin transaction outputs to their controlling addresses
- **Logic**: Extracts Bitcoin addresses from the `scriptPubKey` field of each transaction output, creating a mapping of transaction hash plus output index to the corresponding Bitcoin address. This lookup table enables resolution of which address controls each UTXO (Unspent Transaction Output) in the Bitcoin network.
- **Key fields**: Maps `transaction_hash` and `output_index` to `user_address` extracted from output `scriptPubKey`

### Component B: Active user identification  
- **Purpose**: Identifies which Bitcoin addresses were active (sent transactions) on each day
- **Logic**: For each Bitcoin transaction, examines the transaction inputs which reference previous transaction outputs being spent. Joins these input references with the address resolution lookup table to determine which Bitcoin addresses are spending UTXOs. Groups results by day to identify distinct active addresses per day. The process is split into historical data (pre-2019) and recent data (2019+) for processing efficiency.
- **Key fields**: Links input `transaction_hash` and `output_index` references to resolved `user_address`, aggregated by daily `timestamp`

### Component C: Daily active user aggregation
- **Purpose**: Creates daily distinct counts of active Bitcoin addresses using HyperLogLog sketches
- **Logic**: Converts daily active addresses into HyperLogLog (HLL) sketches to enable efficient approximate distinct counting. Creates sketches for each day with precision parameter 15, allowing accurate distinct counting while handling large datasets efficiently. Organizes data by multiple dimensions including chain level, user type, and project categories.
- **Key fields**: Transforms `user_address` into HLL sketches grouped by `timestamp`, `chain_id`, `user_type`, and `product_id`

### Component D: Monthly rolling window calculation
- **Purpose**: Calculates 30-day rolling monthly active user counts
- **Logic**: Creates a complete datespine of all days, then generates 30-day rolling windows by joining each day with the previous 29 days. For each window, merges the daily HLL sketches and extracts the final distinct count representing monthly active users. This approach ensures no missing days affect the rolling window calculations and provides accurate distinct counts across the full 30-day periods.
- **Key fields**: Merges HLL sketches over 30-day windows and extracts final `user_mau` counts

### Final aggregation
- **Combining components**: The monthly active user calculation provides multiple dimensional breakdowns (chain-level, project-level, user-type-level, and product-level), which are unioned together into a comprehensive dataset
- **Currency conversion**: No currency conversion required as this is a count-based metric
- **Time aggregation**: Uses 30-day rolling windows with daily precision, ensuring complete coverage without gaps in the time series
- **Final calculation**: Takes the monthly active users metric and renames it to monthly active addresses, reflecting that for Bitcoin blockchain analysis, active addresses and active users represent the same concept - unique Bitcoin addresses that have sent transactions within the rolling 30-day window

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

Unique addresses active over a rolling 30-day window.

Active addresses (monthly)

Bitcoin

Miners process transactions and receive fees from users (supply-side fees).

Bitcoin is a distributed ledger for transfer and store of value (a blockchain). Bitcoin was founded by a pseudonym Satoshi Nakamoto and launched in 2009.

BTC holders own and govern the protocol. They currently do not take a cut of the total transaction fees paid by users (revenue).

BitcoinBTC

Active addresses (monthly)

Active addresses (monthly)

Competitive landscape