The public availability of the entire history of Bitcoin transactions opens up the unprecedented possibility of studying this system at the desired level of detail. Our contribution is intended to analyse the mesoscopic properties of the Bitcoin User Network (BUN) during the first half of its history, ie, across the years 2011-2018. What emerges from our analysis is that the BUN is a core-periphery structure with a certain degree of “bow-tieness”, ie, admitting the presence of a Strongly-Connected Component (SCC), an IN-component (together with some tendrils attached to it) and an OUT-component. Interestingly, the evolution of the BUN structural organisation experiences fluctuations that seem to be correlated with the presence of “bubbles”, ie, periods of price surge and decline observed throughout its entire history. Our results, thus, further confirm the interplay between structural quantities and price movements reported by previous analyses.
