Whisper it gently if he is within earshot, but Sean Healey’s $700 billion Affiliated Managers Group is not immune from the challenges facing active managers.

It may be big, and it may have enjoyed years of growth from its stakes in fund managers, but its latest numbers tell an all too familiar story. In the second quarter of this year, AMG's net inflows fell to $600 million - against $4 billion a year ago - as cheap passive strategies won the lion's share of new business. Even before writing off acquisition costs, its net income from stakes in its 40 affiliate boutiques fell 3% to $166.5 million, reversing annualised growth of 30% in the five years to 2015.