Supermarkets have been having a bad time. In groceries, the giants are continuing to lose business to smaller independents. In banking too, the big battalions have lost out to simpler and nimbler insurgents since the financial crisis.

In deal advice, a new breed of specialists has grabbed a large chunk of market share. Yet, more recently, something rather curious has happened. The drift from the financial supermarkets to the boutiques appears to have stopped. What is going on?