In December 2015, O’Brien LLP won the reversal, on appeal, of a judgment that had been entered against its client, a fund manager, in a dispute concerning the client’s entitlement to fund profits.

In September 2015, the New York Times published a letter written on behalf of O’Brien LLP client Reaz Islam.

In June 2015, O’Brien LLP obtained the complete dismissal, following an arbitral hearing, of multi-million dollar claims brought against a private investment firm based upon the alleged breach of a fund-raising agreement and related fraud.

In May of 2015, O’Brien LLP obtained the affirmance, on appeal, of a summary judgment ruling that it had obtained on behalf of a hedge fund, in which the court dismissed multi-million dollar claims for compensation and attorneys’ fees brought by former employees.

In February 2013, O'Brien LLP won a $12.7 million verdict, including $6 million in punitive damages, on behalf of a hedge fund manager against a public REIT, proving claims of fraud and breach of fiduciary duty.

Sean O'Brien was appointed to the United States Court of Appeals for the Second Circuit Pro Bono Panel in August of 2012.

O'Brien LLP sponsored and coordinated "The Fourth Amendment in the 21st Century," a Federal Bar Council CLE Program held on May 23, 2012.

"Sean R. O'Brien Launches Boutique Law Firm Focused on Hedge Fund Litigation," Hedge Fund Law Report, Vol. 4, No. 40 (Nov. 10, 2011).

O'Brien LLP was a sponsor of the Fifth Annual Hedge Fund General Counsel Summit held on September 13, 2011.

"New York State Supreme Court Dismisses Intentional Infliction of Emotional Distress Claim in Suit by Former Employees Against Hedge Fund Manager Touradji Capital," The Hedge Fund Law Report, June 11, 2010.

"Amaranth Withdraws $350 Million Case Against Touradji Capital,", November 17, 2009.