Tourmaline Partners, LLC Announces Key Hires, Tim O’Halloran and Sean Riley


STAMFORD, Conn., Oct. 18, 2016 — Tourmaline Partners, LLC, a global institutional equity and derivatives trading firm, is pleased to announce a significant senior-level management expansion to address a growing demand for its outsourced trading services.   Tourmaline has hired two senior industry executives, Tim O’Halloran and Sean Riley, to join their team in their Stamford, CT headquarters. 

Most recently, Mr. O’Halloran was Co-President of Westminster Research Associates LLC, which he co-founded in 1993.  He shared responsibility for all facets of the business, including P&L, strategy, implementation, operations, and compliance, as well as leading Westminster’s brokerage relations and independent research initiatives.  Mr. O’Halloran positioned Westminster Research to become an industry leader in the management of CSAs and CCAs and a thought leader in the commission management space. 

Before joining Tourmaline, Mr. Riley was a founding Partner, Managing Director, and Head of Trading for Glade Brook Capital Partners where he was responsible for the firm’s global trading. Prior to joining Glade Brook, Mr. Riley was at Shumway Capital Partners where he was a Managing Director and Head of Trading.  Prior to Shumway, he was a senior trader at GLG Partners.

“Tourmaline provides a differentiated offering that lends itself perfectly to an unbundled marketplace.  I’m pleased to be able to join Tourmaline during an exciting growth phase and bring their client-driven approach to new firms and markets,” said Tim O’Halloran.

“As an independent, employee-owned firm, Tourmaline’s interests are fully aligned with those of its clients,” said Mr. Riley.  “The firm’s unique structure provides superior access to liquidity, information, and expertise.  I am excited to join the Tourmaline team and look forward to leveraging my years of buy-side experience on behalf of our current and future clients.”

“We are fortunate to add Sean Riley and Tim O’Halloran to Tourmaline’s leadership team,” said Aaron Hantman, Chief Executive Officer.  “Both Tim and Sean bring a wealth of talent, knowledge, and experience to Tourmaline and add immediate value to our clients.”

Tourmaline Partners, LLC is a global institutional equity trading firm with offices in Stamford, CT and London, UK.  Tourmaline functions as a 100% conflict free trading partner, with no proprietary trading, research or banking.   Tourmaline’s unique structure provides clients with unparalleled access to natural liquidity, global market reach, and operational compliance. Tourmaline’s flexible solution serves emerging funds seeking trading expertise and economies of scale, larger industry players seeking anonymity and broader access to liquidity, and multi-manager platforms.  Tourmaline Partners, LLC is registered with the SEC and FINRA.  Tourmaline Europe LLP Is a wholly owned subsidiary authorized and regulated by the FCA.

To find out more about Tourmaline Partners, LLC please contact Aaron Hantman at 203.302.7300 or