What do Ronald Williams, Jim McNerney, and Kenneth Chenault have in common? 

They are the three most popular board directors at the 30 companies that make up the Dow Jones Industrial Average. 

RJ Andrews, who runs the Info We Trust blog, mapped out the board member overlap at DJIA companies.

The research is based on Bloomberg data and includes common board members only. 

He told Business Insider he initiated the data project to see just how interconnected Wall Street truly is. 

The result is a spider’s web connecting some of the biggest companies in America.

Chenault is still the sitting CEO and chairman of American Express, and also sits on the boards of IBM and Procter & Gamble. 

Williams, who used to run Aetna, sits on the boards of Boeing, Johnson and Johnson, and American Express. 

Jim McNerney stepped down from CEO role at Boeing at the end of June, but continues to act as chairman. He also serves on the boards IBM and Procter & Gamble.

American Express declined to comment. Boeing, IBM, and Procter & Gamble did not return calls seeking comment in time for publication. 

There are a further 63 executives who sit on two boards, according to Andrews’ analysis. Only three companies — The Home Depot, Verizon, and UnitedHealthcare — had no board member overlap with other DJIA constituents.