Turnover of CEOs at FTSE 100 companies is on pace for an all-time record in 2019, with 14 bosses having left or announced plans to leave their posts so far this year.
HSBC's John Flint became the latest casualty on Monday, after the bank announced it needed a change in leadership after just 18 months with Flint at the helm.
To put the rate of attrition into context, a total of 18 CEO changes were announced in 2018, itself well above of the annual average since 2011 of 12, and the highest figure since 2007.
There are three factors at work in businesses' ravenous appetite for change, according to AJ Bell investment director Russ Mould.
First, the FTSE 100 has struggled to make headway over the past 18-24 months. The British blue chip index was trading at around 7,199 Thursday afternoon after a positive session, only around 3.8% higher than its peak in December 1999.
Mould suggested that this sluggish performance has increased the level of pressure on CEOs from fund managers to perform, since they in turn are under growing pressure from investors. The next factor is the lower for longer environment.
"Cash is earning nothing in the bank for companies so managers are under pressure to do something smart with it to conjure up growth in a low interest rate, low growth, low inflation environment or just give it back to investors," Mould told CNBC on Thursday.
The third source of pressure is primarily U.S.-based activist investors "raising the temperature," he added.
Activist investors are individuals or groups that purchase substantial amounts of shares of a public company in an attempt to obtain seats on the board and change how it operates.
"There are so many of them now that they are branching out of their domestic hunting ground (the U.S.) and looking overseas," Mould explained.
"When they come, they come with their classic checklist of options — operational change, financial change, strategic change or, wait for it, management change."
Reasons to be leaving
Of the 14 companies to announce changes at the helm this year, nine have already left, with one more to go in 2019, while the remaining four will step down in 2020.
In some instances, departures can be directly linked to poor share price performance or obvious failings. One example would be Centrica, Mould highlighted, which announced in July that it would part with CEO Iain Conn next year, with the company's share price down 70% since his tenure began in 2015.
In HSBC's case, while the share price has not done particularly badly, performance of the European and American operations has continued to disappoint investors.
Just Eat parted company with CEO Peter Plumb in January with immediate effect, after just 16 months on the job, in which he launched an investment drive which slowed earnings growth.
American activist investor Cat Rock Capital was extremely vocal about the food delivery website's dwindling performance, and has since got its way in the form of a recently confirmed tie-up with Dutch rival Takeaway.com.
Some resignations have been more harmonious, coming about as a result of either investors or the CEO feeling "ready for a fresh challenge or a break," Mould suggested.
"Direct Line, BAT, Ashtead, Auto Trader and Unilever would fit this category, as all five men here left of their own volition at a time of their choosing, generally after a job very well done," he said.
A final factor in recent departures has been decisions on the part of CEOs to shore up their legacy.
"Reckitt Benckiser is a possible example here, as no sooner had Rakesh Kapoor left than the firm issued a weaker-than-expected trading update that again raised questions about the wisdom of 2017's purchase of Mead Johnson," Mould said.