Eight decades of shouldering the burden of investors’ anxieties has left its mark on the 61 partners who run the asset management arm of William Blair & Co, a Chicago financial services firm that is extending its product range in Europe.

Michelle Seitz, William Blair's otherwise-upbeat head of investment management, is concerned about her firm's shortcomings during the financial crisis and, in particular, in 2008: "We did our job. We beat the benchmark. But we failed to recognise that the benchmark didn't matter any more.