Rare is the start-up that has 300 employees and customers as prestigious as Blackstone Alternative Asset Management and D.E. Shaw & Co. on day one. That was the good fortune of Arcesium, a posttrade services specialist that D.E. Shaw spun out of its own operations in 2015 with a management team led by Gaurav Suri, who had been the renowned, high-tech hedge fund firm's head of information technology and software development. The venture's name is derived in part from "cesium," the chemical element used in atomic clocks, to connote operational precision.
Arcesium is growing at a healthy clip, offering a "cloud-based, co-sourced" service model that allows hedge funds to maintain control over treasury, operations, and accounting functions performed on the firm's state-of-the-art platform — while having access to staff expertise in accounting, operations, technology, and treasury. Head count has increased to 650, occupying expanded space in New York and Hyderabad, India, and assets supported have risen to $65 billion, from $40 billion at the start. Clients added over the past year include EJF Capital, an Arlington, Virginia–based alternative-asset management firm, with $5 billion under management; and Balyasny Asset Management, which has offices in the U.S., the U.K., and Hong Kong and $13 billion under management. Suri, 46, who has a master's degree in computer science from the University of Illinois and joined D.E. Shaw in 1996 from Bell Laboratories, says there are additional growth outlets: "We are in conversations with a broad array of financial players beyond hedge funds who could benefit from the platform, including private equity managers, traditional asset managers, and global custodians."
 2. Chris Isaacson Bats Global Markets  3. Bradley Peterson Nasdaq  4. Brad Levy MarkitSERV  5. Dan Keegan Citi |
 6. Glenn Lesko Bloomberg Tradebook  7. Bryan Durkin CME Group  8. Mayur Kapani Intercontinental Exchange  9. Mike Blum KCG Holdings  10. Raj Mahajan Goldman Sachs Group |
 11. Ronald DePoalo Fidelity Institutional  12. Nick Themelis MarketAxess Holdings  13. Jenny Knott NEX Optimisation  14. Billy Hult Tradeweb Markets  15. Rob Park IEX Group |
 16. Bill Chow & Richard Leung Hong Kong Exchanges and Clearing  17. John Mackay (Mack) Gill MillenniumIT  18. Paul Hamill Citadel Securities  19. Eric Noll Convergex  20. Veronica Augustsson Cinnober Financial Technology |
 21. Tyler Moeller & Joshua Walsky Broadway Technology  22. Alasdair Haynes Aquis Exchange  23. Gaurav Suri Arcesium  24. Manoj Narang Mana Partners  25. Michael Chin & Neill Penney Thomson Reuters |
 26. Robert Sloan S3 Partners  27. Anton Katz & Stephen Mock AQR Capital Management  28. Donal Byrne Corvil  29. Stu Taylor Algomi  30. Alfred Eskandar Portware |
 31. Steven Randich Financial Industry Regulatory Authority  32. R. Cromwell Coulson OTC Markets Group  33. Peter Maragos Dash Financial  34. John Fawcett Quantopian  35. Donald Ross III PDQ Enterprises |
 36. Jennifer Nayar Vela Trading Technologies  37. Dan Raju Tradier  38. Susan Estes OpenDoor Trading  39. David Mercer LMAX Exchange  40. Oki Matsumoto Monex Group |
