Mainstream in the United States

Our US fund administration service offers investment managers a conduit into the largest hedge fund and private equity markets in the world.

Mainstream Fund Services is a full-service fund administration firm dedicated to partnering with their clients to provide accurate, timely and comprehensive accounting services to the financial services industry.

With offices in the New York City metro area and clients around the world, Mainstream’s highly professional and seasoned associates provide world class service, transparency and oversight along with independent data verification. Cutting edge technology is fully automated, flexible and provides a cost-effective level of reliability that meets the specific needs of sophisticated investors.

Our experts provide private equity, real estate, venture capital, and hedge fund managers with the following services:

  • Accounting and Fund Administration
  • Investor Relations
  • Treasury
  • Compliance
  • Audit and Tax Support

New York, United States Office

  • Apex Fund Services (Indiana), Inc
  • 420 Lexington Avenue, Suite 2260 New York, NY 10170 USA
  • +1 212 802 7980

Ronkonkoma, United States Office

  • Apex Fund Services (Indiana) Inc.
  • 4175 Veterans Memorial Highway, Suite 202, Ronkonkoma, NY 11779 USA
  • +1 212 802 7980

Indiana, United States Office

Miami, United States Office

Senior Management Team

Jay Maher
Chief Executive Officer, Americas

Jay is a recognized leader in private equity administration. Jay began his fund accounting career in 1993 for Merrill Lynch. He then became a pivotal team member in the growth of Geller Investment Partnership Services, a boutique private equity administrator. Jay went on to be a founding partner of Northport Partnership Services in 2004, providing specialized services to PE, VC, and RE Fund Managers. Jay and his partners gained significant traction in the market and partnered with SS&C to expand their offering.

Northport was acquired by SS&C Inc. in 2007 and Jay became the Global Head of Private Equity. Under Jay’s leadership the business grew from $3 billion in Assets under Administration to $150 billion.  Jay left SS&C in 2015 and has partnered with Mainstream to buildout his team’s current offering, which is an evolution of Jay’s success over the past 25 years.  Jay has developed the industry’s best workflow processes focused on technology.  He has developed a deep pipeline of business feeders throughout his career, and works closely with the industry’s best audit, consultant, and legal teams.

Jay earned an B.S. in Accounting from Rowan University.

James Wheatley
President, Americas

James has over 16 years of fund accounting experience, with a particular focus on private equity, direct lending and real assets.

James began his fund accounting career with Saints Venture Capital before joining Babcock & Brown’s private equity group (who later spun out to form SteelRiver Infrastructure Partners). James then helped build out SS&C’s Los Angeles based PE team before joining Ultra Capital, a newly established project finance and asset management company specializing in renewable energy and sustainable infrastructure as the VP of Finance. He joined Mainstream in 2018 as part of the Group’s expansion into closed-end fund services.

James has a Bachelor of Science in Accounting and Finance from Northeastern University, and a Master of Science in Accounting from Golden Gate University.

Senior Vice President - Private Equity, Venture Capital, Real Estate

Gary has over 18 years of accounting experience, with 13 years in the private equity fund administration space. Gary joined Mainstream PE Fund Services as Senior Vice President in 2018.

Gary’s tenure within fund administration began in 2005 with a fund accounting role at Northport Partnership Services, which was later acquired by SS&C Technologies in 2007. During his time there, Gary’s success allowed him to ultimately lead a team in the private equity group administering over $20 billion in AUM across complex alternative investment structures, including private equity, fund of funds, venture capital, real assets, and hybrid structures. Prior to Gary’s fund administration career, he worked for Chubb Insurance Company as an accounting analyst for 5 years covering catastrophe claims.

Gary has earned a Bachelor of Science in finance from Fairleigh Dickenson University.