Methodology and data sources
This page lists where every number on Blockdeck comes from, how often it refreshes and what its limits are.
Sources and refresh rates
Price and market data is provided by CoinGecko.
| Data | Source | Refresh |
|---|---|---|
| Prices, market cap, volume, supply, all-time highs, 1h to 30d change | CoinGecko | every few minutes |
| Price charts and candlesticks | Exchange spot market data, CoinGecko as fallback | 1 minute to 6 hours, by range |
| Total market cap, BTC and ETH dominance | CoinGecko | every 5 to 30 minutes |
| Trending coins | CoinGecko search trends | every 10 to 60 minutes |
| Categories and sector coin lists | CoinGecko categories | every 1 to 12 hours |
| Heatmap and Altcoin Season Index | Calculated by Blockdeck from the price data above | with prices |
| Crypto Fear & Greed Index | alternative.me | daily |
| Bitcoin network fees | mempool.space | every 2 minutes |
| Ethereum gas price and slow / standard / fast tiers | Public Ethereum node (eth_gasPrice, eth_feeHistory over 20 blocks) | every 2 minutes |
| News headlines | Publisher RSS feeds (CoinDesk, Cointelegraph, Decrypt, Bitcoin Magazine) | every 3 minutes |
| Funding rates, open interest, long/short (VIP) | Perpetual futures markets | every 2 minutes |
| Liquidations (VIP) | Futures liquidation feed | live |
| Whale transfers, exchange flows, stablecoin mints and burns | Read by Blockdeck from the Bitcoin, Ethereum and Tron blockchains through public nodes; exchange wallets from an open label dataset and our own checks | every block (12 seconds to 10 minutes) |
| Daily Market Brief | Written by Claude (Anthropic) from the Blockdeck data on this page | daily at 04:00 UTC |
| Story briefs on news pages | Written by Claude (Anthropic) from the headline, the feed excerpt and our price data | as stories arrive |
How coin pages are written
The explanation on each coin page is generated from that coin's live data every time the page refreshes: its price range today, its rank against the coins next to it, how its trading volume compares with the top 100, its supply and its distance from its all-time high. The text describes measured facts. It never predicts prices or tells anyone to buy or sell.
Indexes we calculate
The Altcoin Season Index is the share of the 50 largest altcoins that beat Bitcoin over 30 days (and 7 days, shown next to it), leaving out stablecoins and wrapped, staked or bridged copies of other coins. The heatmap shows the 100 largest coins on the same basis, with tile area proportional to the square root of market cap so smaller coins stay readable.
News
We show headlines and a short summary, tag them by coin and topic, and credit the original publisher on every story. We do not republish full articles.
Known limits
Third-party data can be delayed or wrong. When a source fails, Blockdeck keeps showing the last good data and marks it as updated earlier. Liquidation totals are observed figures from a public stream that publishes a sample of events, so they are a lower bound. Funding rates are converted to an 8-hour basis so coins with different settlement intervals can be compared.
Corrections
If you spot a wrong number or a broken source, tell us and we will fix it.