"Business is just a set of problems to solve," Seth Merrin writes in The Power of Positive Destruction, a combination personal memoir and entrepreneurial how-to manual published in December. "It's really the book of Liquidnet," that is, the company he founded and went live with in 2001 with a trading platform for institutions whose large stock orders had become too difficult to transact on traditional exchanges. A lot of sweat went into growing the network from 38 buy-side firms at the start to more than 850 today, trading in 44 markets around the globe. That's not to mention the bumps along Merrin's career path and in multiple startups, including Merrin Financial, which pioneered the buy-side trade order management system. "I made tons of mistakes," he admits, now hoping others can learn from his experiences. As the title of the book, co-written with Carlye Adler, suggests, the Liquidnet Holdings CEO, 57, remains every bit the entrepreneur scoping out opportunities for disruption. "We are in institutional fintech," he says, noting that about a third of Liquidnet's 400-plus employees are technologists. "That is our core competency," he adds. In the book he urges that technology be embraced as a competitive advantage, but adds: "Understand that with the pace of technological change, the disrupter can easily become the disrupted. Positive destruction must be constant."
 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 |