A High Yield Investment Program (HYIP) is an online Ponzi scheme, a financial fraud that pays outrageous levels of interest using money from new investors. Despite being illegal to operate in most jurisdictions, there are many active HYIP websites at any given time.

We call them 'postmodern' Ponzi schemes because we believe that many of the investors are well aware of the fraudulent nature of the sites, but believe that by investing at an early stage – and withdrawing their money before the scheme’s collapse – they will be able to make a profit at the expense of less savvy investors.

An extensive online ecosystem has developed in support of HYIPs, involving discussion websites, digital currencies, and third-party ‘aggregator’ websites that track HYIP performance. These aggregators list dozens of active HYIPs, tracking core features such as interest rates, minimum investment terms and funding options. They operate forums in which individuals can report their experiences; but more significantly, the aggregators appear to make their own investments in some of the HYIPs and report on when interest payments cease.

We have spent many months collecting data from HYIP websites and aggregators to measure the extent of HYIP activity, so that we can improve our understanding of this particular type of online criminality. We have found no evidence of collusion between different aggregators. We use their data to assess HYIP time to collapse, finding – perhaps unsurprisingly – that longer lifetimes are associated with lower interest payments and longer mandatory investment terms. We look at the role of digital currencies in supporting HYIPs, finding that a handful of systems dominate. Finally, we estimate that this type of criminality is turning over at least $6 million/month and set out ways in which it might be disrupted.