RaveReutersClark and Louch[\'s]...excellent book, which is more true crime than finance, describes in cinematic detail how Naqvi and his colleagues pumped up valuations, moved money between the company, its funds and their personal accounts, and lied about performance. It was a classic Ponzi scheme that needed to keep raising ever bigger sums to keep going ... raises uncomfortable questions for impact investing, which aims to deliver social or environmental benefits alongside returns for investors.