When Lou Eccleston took over as chief executive officer of Toronto's TMX Group in 2014, he promptly began throwing words like "entrepreneurial" and "technology driven" around what had been a staid exchange-operating holding company. Eccleston set TMX — the owner of trading venues including the Toronto Stock Exchange, Montreal Exchange, and TSX Venture Exchange — on course to being a global technology-enabled services business, while seeking to reverse multiple down years on the bottom line. He had already established a reputation for being unabashed in his embrace of digital disruption in his previous role as president of McGraw Hill Financial's S&P Capital IQ, where his culture-changing efforts included the creation of an innovation hub with Google-like workspaces and amenities. At TMX, Eccleston accomplished a turnaround to what he calls "profitable growth, achieving both record revenue and earnings while continuing to pay down significant amounts of debt" in 2016. In the first quarter of this year, revenue rose 5 percent from a year earlier to $186 million, and income from operations jumped 17 percent to $81 million. "This is the strongest digital effort I have ever been involved in," says Eccleston. At age 60, he says it's full speed ahead.
 1. Adena Friedman NASDAQ  2. Catherine Bessant Bank of America Corp.  3. Robert Goldstein BlackRock  4. Jeffrey Sprecher Intercontinental Exchange  5. Lance Uggla IHS Markit |
 6. Shawn Edwards & Vlad Kliatchko Bloomberg  7. David Craig Thomson Reuters  8. Michael Spencer NEX Group  9. Don Callahan Citigroup  10. Elisha Wiesel Goldman Sachs Group |
 11. Michael Bodson Depository Trust & Clearing Corp.  12. Terrence Duffy CME Group  13. Charles Li Hong Kong Exchanges and Clearing  14. Sean Belka Fidelity Investments  15. Chris Concannon CBOE Holdings |
 16. Guy Chiarello First Data Corp.  17. Steven Lieblich Citadel  18. David Rutter R3CEV  19. Blythe Masters Digital Asset Holdings  20. Alfred Spector Two Sigma Investments |
 21. Neil Katz D.E. Shaw Group  22. Lee Olesky Tradeweb Markets  23. Richard McVey MarketAxess Holdings  24. David Gledhill DBS Bank  25. Seth Merrin Liquidnet Holdings |
 26. Antoine Shagoury State Street Corp.  27. Peter Brown & Robert Mercer Renaissance Technologies  28. Lou Eccleston TMX Group  29. Peter Cherecwich Northern Trust Corp.  30. Mike Chinn S&P Global Market Intelligence |
 31. Chris Corrado London Stock Exchange Group  32. Neal Pawar AQR Capital Management  33. Gary Norcross Fidelity National Information Services  34. Steven O'Hanlon Numerix  35. Sebastián Ceria Axioma |
 36. Brian Conlon First Derivatives and Kx Systems  37. Tyler Kim MaplesFS  38. Michael Cooper BT Radianz  39. Robert Schifellite Broadridge Financial Solutions  40. Jim Minnick eVestment |