In just the last 24 hours, the CEOs of WeWork, eBay and Juul have all stepped down from their posts, the continuation of a record-setting pace of exits this year by the heads of U.S. businesses.

U.S. based companies announced 159 CEO changes in August, 28% higher than the 124 CEO exits in July and the most ever in a month, according to business and executive coaching firm Challenger, Gray & Christmas. Through August, there were 1,009 U.S. CEO departures in 2019, according to Challenger, more than at the same point in 2008 when the economy was embroiled in the financial crisis.

Experts says there has been a shift to more accountability because of worries about the slowing economic expansion, which has been the longest in U.S. history.

"CEOs are now being held on a shorter leash," said Jeffrey Sonnenfeld, a senior associate dean at the Yale School of Management. "When the puffery and the rhetoric doesn't match reality, the boards are under pressure to hold the CEOs accountable."

2008 was the second-highest year for CEO turnover with 992 executives leaving through August, 2% lower that the current year-to-date performance.

"With growing uncertainty surrounding global business and market strength, the fact that so many companies are choosing this moment to find new leadership is no coincidence," said Andrew Challenger, Vice President of Challenger, Gray & Christmas, in a release.

Amidst talks about going public, WeWork's CEO Adam Neumann announced Tuesday he was stepping down from the coworking rental space company after an uproar over governance.

Controversial e-cigarette company Juul said Wednesday its CEO Kevin Burns resigned, and will be replaced by former Altria executive K.C. Crosthwaite. Hours later, eBay said its president and CEO Devin Wenig is leaving as the company moves forward with potential sale of assets.

Volkswagen, Nissan and Comscore all lost their chief executives this month.