A Bank for International Settlements working paper found that Bitcoin on-chain transfer estimates can differ by as much as sixfold, depending on how researchers treat transaction outputs, change and self-transfers. Published on 15 September 2026 as BIS Working Paper 1377, the study was authored by Timothy Aerts, Ronald Heijmans, Jan Paulick and Violeta Vuletic. Its Bitcoin analysis covered 2009 through 2026, including approximately 1.3 billion transactions and 3.6 billion transaction outputs. The paper compared broad, adjusted and conservative approaches to measuring transfers, while warning that even the most cautious estimate is a heuristic. It also found that conventional Bitcoin market capitalization had at times reached four times realized capitalization and that more than 1.8 million BTC had remained untouched for over 15 years. CoinGecko data cited in the study put Bitcoin at about $75,795, with a market capitalization of approximately $1.52 trillion, circulating supply of 20.09 million BTC and 24-hour trading volume of around $39.3 billion. The research also identified substantial classification gaps on Ethereum and differing uses for USDT across Ethereum and Tron. Visa's Onchain Analytics dashboard showed $6.4 trillion in total stablecoin volume against $313.1 billion in adjusted volume over the prior 30 days. The authors recommended ranges and explicit methodological assumptions instead of single-point on-chain estimates.