Bitcoin (BTC) is the settlement asset of the Bitcoin blockchain. Supply is capped at 21 million coins with a predictable issuance schedule (halvings). It is priced continuously on spot venues and has deep derivatives markets (perpetuals, dated futures, options).
Research use: BTC often serves as the beta factor for crypto risk. Watch miner economics, ETF/flow data where relevant, realized volatility, and the futures basis/funding complex. Custody and UTXO dynamics matter for operational and on-chain analysis; they are not substitutes for market structure.