Asset managers like to see two thirds of their funds beat their benchmarks. High-quality – or lucky – managers can achieve 80% from time to time. But US-based MFS Investment Management, which manages nearly $250bn, has done even better in the virility stakes, with more than 95% of its institutional accounts outperforming over three and five years. Its retail funds have achieved 84%.

It is difficult to get much better than this and, this year, the performance of several strategies within MFS has dipped. Only 57% of its retail funds have beaten their benchmark over the last 12 months.