Anthony Bolton and Bill Mott, two of the biggest stars running funds for private investors, horrified bosses and investors last year when they announced their retirement. They were just two of many in the investment industry.

Michael Taylor, head of equities at Threadneedle, gained a high profile in some of the most talked about bids last year. He quit the City in December, as did Keith Jones, chief executive of Morley Fund Management, the UK's fourth-biggest.