“Quantitative Analysis of the Full Bitcoin Transaction Graph,” by Dorit Ron and Adi Shamir:

Abstract. The Bitcoin scheme is a rare example of a large scale global payment system in which all the transactions are publicly accessible (but in an anonymous way). We downloaded the full history of this scheme, and analyzed many statistical properties of its associated transaction graph. In this paper we answer for the rst time a variety of interesting questions about the typical behavior of account owners, how they acquire and how they spend their Bitcoins, the balance of Bitcoins they keep in their accounts, and how they move Bitcoins between their various accounts in order to better protect their privacy. In addition, we isolated all the large transactions in the system, and discovered that almost all of them are closely related to a single large transaction that took place in November 2010, even though the associated users apparently tried to hide this fact with many strange looking long chains and fork-merge structures in the transaction graph.