Innovation is systematic within D.E. Shaw & Co., the $42 billion alternative-investment firm founded in 1988 by computer scientist and computational finance pioneer David Shaw. Rather than reacting to the latest trends in the IT world, D.E. Shaw relies on the continuous experimentation of its decentralized IT teams, whose good ideas may catch on across the firm. A few years ago, for example, a more efficient framework for quote distribution and market-data dissemination was developed by one group and eventually adopted by others, says managing director Neil Katz, 45, who has been with D.E. Shaw since his 1994 graduation from Stanford University. Katz, who earned degrees in electrical engineering and quantitative economics, manages a team of more than 250 technologists. They participate in hackathons, including an annual competition in India that exposes developers to technologies that might be useful in their regular work. There are also occasional hack weeks in New York, where people are encouraged to work on projects outside their regular priorities. "We've seen some real breakthroughs when people put aside their normal workflow and turn to whatever side projects interest them," Katz says.
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 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 |