Before revision:  In this paper, we comprehensively study the changing trend of the default rate of P2P USA market at the aggregative level from August 2007 to January 2016.
After revision:  Different from previous studies that focus on modeling the default rate at the individual level, in this paper, we comprehensively study the changing trend of the default rate of P2P USA market at the aggregative level from August 2007 to January 2016.