This paper provides the necessary technical background to understand basic Bitcoin operations and documents a set of empirical regularities related to Bitcoin usage. We present the micro-structure of the Bitcoin transaction process and highlight the use of cryptography for the purposes of transaction security and distributed maintenance of a ledger. Using publicly available transaction-level data, we examine patterns of general usage together with usage by Satoshi Dice, the largest online gambling service using Bitcoin as the method of payment. Our analysis suggests that less than 50 percent of all bitcoins in circulation are used in transactions. About half of these transactions involve less than U.S.$100 equivalent, and for the period for which we have data for Satoshi Dice, most of these small-value transactions were related to the online gambling service. Relatively less frequent large value transactions drive the average transaction value to levels above U.S.$40,00 0 equivalent value, and are not likely to involve payments for goods and services. Bitcoin exchange rates exhibit somewhat complicated dynamics. In the past 24 months, the USD-BTC exchange rate increased more than 50-fold. The daily variance of the USD-BTC exchange rate remained remarkably stable for this same period, once the variance calculations account for the changing exchange rate level. We also document that the exchange rates between bitcoin and other major currencies are not well aligned. We interpret this as lack of depth of the exchange markets and as costly exchange rather than as unexploited arbitrage opportunities. Finally, we examine the economic incentives for the participants in the distributed implementation of the Bitcoin scheme.
