Characterizing key agents in the cryptocurrency economy through blockchain transaction analysis Xiao Fan Liu, Huan-Huan Ren, Si-Hao Liu and Xian-Jian Jiang EPJ Data Sci., 10 1 (2021) 21 Published online: 01 May 2021 DOI: 10.1140/epjds/s13688-021-00276-9