Index Overview
The Coin Metrics Bletchley Indexes ("CMBI") are an independent, transparent, and comprehensive measure of cryptoasset market performance and network activity. They are used as benchmarks, as settlement references, and as the basis for investable products by crypto-native and traditional financial institutions.
Coin Metrics also distributes index data produced by third-party index providers, served through the same endpoints and the same schema as its own indexes. So the index universe on this API is wider than the CMBI series alone, and a page in this section may apply to both. Where the two behave differently, the data-type pages say so.
Index Families
Coin Metrics calculates several distinct index series, each governed by its own published methodology.
CMBI Single Asset Series
The market value of one cryptoasset, aggregated across a vetted set of eligible markets rather than taken from any single venue
CMBI Multi Asset Series
The performance of a defined basket, weighted either by free-float-adjusted market capitalization or equally across constituents
CMBI Total Market Series
Broad and sector-level market coverage, including thematic sector baskets
CMBI Momentum Series
A rules-based strategy that tilts toward assets with recent relative strength
CMBI Mining Series
Network work and hash rate rather than price, so its levels are derived from on-chain data
CMBI Ethereum Staking Index
The total return of purchasing and staking Ether, combining the price return with staking rewards
CMBI Derivative Fixings
A once-daily fixing intended as a settlement reference for derivatives contracts
The distributed third-party series cover much the same ground, single-asset benchmark rates and multi-asset baskets, and they also extend beyond crypto into traditional-finance benchmarks such as interest rate series. A third-party index identifier is prefixed with its provider's short code, which is how you tell it apart from a CMBI index at a glance. The coverage tool lists every index with its full name, category, and available history.
Choosing a Data Type
Three timeseries data types are published for indexes, and each describes the same index from a different angle. A level is what the index is worth at an instant. A candle is how that level moved across an interval. Constituents are what the index held while it moved. All three are served from the /timeseries/index-* endpoints, and all three cover both CMBI and distributed third-party indexes.
Levels are the primary output, and the other two are derived from them. If you are unsure, start with levels.
One index at one instant
What is the index worth right now, or at this timestamp?
1s, 15s, 1h, 1d, 1d-ny-close, 1d-sg-close, 1d-HH:00
Yes, /timeseries-stream/index-levels
One index over one interval
Where did the index open, close, and range over this interval?
1m, 5m, 10m, 15m, 30m, 1h, 4h, 1d, 1d-HH:00
No
One index's full basket at one instant
What is in the index, and at what weight?
1h, 1d, 1d-ny-close, 1d-ny-midday, 1d-sg-close
No
One thing to know before you query: frequency support is per index, not universal. No index publishes every frequency in its row above, some have no candles at all, and third-party indexes publish their provider's own native frequency instead of the Coin Metrics set.
The Discovery Loop for Indexes
Querying index data follows the same three steps as the rest of the Coin Metrics API. Find out which indexes exist, check what frequencies and time ranges they carry, then pull the data.
2
/catalog-v2/index-levels or /catalog-v2/index-candles
Per index, the frequencies available and the min_time and max_time of each
3
/timeseries/index-levels, /timeseries/index-candles, or /timeseries/index-constituents
The data itself
Step 2 is the one to not skip. Because frequency support varies per index, the catalog is what tells you whether the series you want exists before you request it, and a /catalog-v2/* response reflects your own entitlements while /catalog-all-v2/* reflects the full Coin Metrics universe. There is no catalog endpoint for constituents, so use the index-levels catalog to discover indexes and then query constituents directly.
The indexes parameter on all three timeseries endpoints accepts wildcard patterns such as CMBI* or *BTC, so once you know the universe you can pull many indexes in one call. API Conventions covers paging, response formats, and timestamp handling for every endpoint family.
Governing Documents
Every CMBI series is administered under a published methodology and a common set of policies, which is what makes an index level reproducible and auditable rather than proprietary.
Methodologies: the versioned methodology document for each series, plus the Adjusted Free Float Supply Methodology that determines constituent weights, the Candidate Market Guidelines that determine which markets are eligible inputs, and the Fork Legitimacy Framework.
CMBI Index Policies: the actions Coin Metrics takes to manage specific market or index events, including recalculations and material changes.
Governance Committees: the oversight structure behind those decisions.
Coverage
The coverage tool is the authoritative list of which indexes exist, which candle frequencies each carries, and what history is available.
Related
Index Levels: the value of an index at a point in time, plus a real-time websocket feed.
Index Candles: open, high, low, and close of an index over fixed intervals.
Index Constituents: the member assets of an index and their weights.
Fact Sheets: summary documents for the Single Asset, Multi Asset, Total Market, and Mining series.
Indexes Glossary: definitions of the index terms used across this section.
Reference Rates: the asset prices that feed multi-asset index calculations.
Market Data Overview: the trades and market data the index inputs are collected from.
Data Visualization: index data in the Coin Metrics charting and exploration tools.
Last updated