Experience

Tourmaline Partners, LLC

• United States
• Financial Services
• 1 - 100 Employee

• Managing Director

  • Oct 2016 - Present

  Mr. O'Halloran joined Tourmaline Partners, a global institutional equity and derivatives trading firm, in October 2016 as a member of the senior-level management team. His responsibilities include sales, marketing and commission management initiatives and helping to drive global growth and revenue. Mr. O’Halloran has spoken at numerous industry conferences and events in both the United States and abroad, and regularly authors thought pieces on the subjects of independent research, institutional and outsourced trading, CSAs and commission management. Show less



Westminster Research Associates LLC

• United States
• Financial Services
• 1 - 100 Employee

• Co-Founder, Co-President

  • Jan 1993 - Jun 2016

  Mr. O’Halloran was a Co-President of Westminster Research Associates LLC, which he co-founded in 1993. Over a 23+ year span 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. Show less


Lehman Brothers
• Capital Markets
• 700 & Above Employee
• Vice President, Worldwide Equities

  • Jun 1985 - Jan 1993