數位通貨：市場與影響

比特幣底層所使用的分散式帳本技術頗具創新，且比特幣開放原始碼，因而吸引不少開發人員據以發展出不同數位通貨，目前總數已超過1,500種。這些數位通貨所形成的新興市場，已引起各界關注。除波動劇烈的市場價格外，一些文獻已開始研究數位通貨與分散式帳本技術所帶來的影響與應用。本文先從比特幣的底層技術及運作機制進行探討，然後歸納數位通貨的分類，並分析其特點與可能的應用場景。為探討數位通貨的報酬、市場風險及市場特性，本文將其與法定貨幣、風險性資產進行比較，發現該市場與傳統金融市場相仿，皆具有厚尾及非線性相關等特性，但其尾端風險卻高出傳統金融資產甚多。本文亦探討數位通貨對使用者、金融機構與市場、央行與貨幣管理機構的影響，以及相關監理議題與監管措施。此外，私部門數位通貨與分散式帳本技術的出現，近來也引起央行是否需要發行數位通貨的議題，爰本文最後討論央行數位通貨的可能種類、設計、發行動機與挑戰。

關鍵字

數位通貨；密碼通貨；區塊鏈；分散式帳本技術；市場風險；監管議題；央行數位通貨

並列摘要

The innovative distributed ledger technology (DLT) underlying Bitcoin has attracted many developers to create a variety of digital currencies based on the source code of Bitcoin, which is an open source. At present, more than 1,500 different digital currencies are available. This rising market that consisted of these digital currencies is also attracting attention. Some studies have been conducted to determine the applications and implications of digital currencies and DLT, in addition to highly volatile market price. This paper studies the underlying technology and the mechanism of Bitcoin and, subsequently, attempts to define the scope of digital currencies and analyze their characteristics and possible applications. By comparing different fiat currencies and risky assets, we discuss the return, market risk, and market characteristics of digital currencies, and we determine that this new market is similar to traditional financial markets having thick tail and nonlinear dependence, while it has much higher tail risk. We explore the implications of digital currencies for end users, financial institutions and markets, central banks and monetary authorities, and we also study some related oversight issues and regulatory measures. The emergence of DLT and digital currencies issued by the private sector has also caused the discussion on introducing central bank digital currencies; therefore, we research its categories and designs, as well as some reasons and concerns.