A longtime litigation partner at Cravath Swaine & Moore has left the storied New York firm to launch a litigation boutique.
Benjamin Gruenstein departs after 14 years as a partner at Cravath, where he was a founding member of the investigations and regulatory enforcement practice. His new firm – Gruenstein Law – will advise companies, their boards of directors and senior executives, with a focus on government and internal investigations, white-collar criminal cases, regulatory enforcement and complex civil litigation.
“The practice of law is undergoing monumental changes,” said Gruenstein. “I look forward to building a law firm from the ground up that delivers premier legal services using small teams of exceptional lawyers, augmented by the transformative legal technology now available. This is an exciting time for lawyers and clients who are looking for cutting-edge, strategic and efficient representation.”
Gruenstein spent five years as a federal prosecutor in the US Attorney’s Office for the Southern District of New York before joining Cravath in 2008 and making partner in 2012. He focuses on government and internal corporate investigations in areas including money laundering, healthcare fraud, trade sanctions, insider trading, the Foreign Corrupt Practices Act and securities and accounting fraud, as well as accompanying civil litigation.
At Cravath, he won the dismissal of a putative securities class action filed against Occidental Petroleum in New York state court relating to securities offerings conducted in connection with Occidental’s $57bn acquisition of Anadarko Petroleum in 2019.
He also won dismissal of a shareholder derivative suit filed in New York Supreme Court against directors and officers of Novartis, alleging that the defendants breached their fiduciary duties to Novartis by failing to conduct adequate oversight of the company’s operations, according to the American Law Institute.
Gruenstein’s departure from Cravath comes just a few months after John Buretta, former chair of the firm’s investigations and regulatory enforcement practice, left to oversee the litigation practice at Paul Hastings.
Gruenstein is the fifth Cravath partner whose departure has become public this year, marking a rare string of defections from a partnership known historically for its stability.
Also in 2026, financial institutions group head and Washington DC office managing partner Jelena McWilliams left for fintech Plaid, while tax lawyer Andrew Davis left for Paul Hastings and national security lawyer Ben Joseloff moved to Davis Polk & Wardwell, Bloomberg Law reported.
Gruenstein’s exit also continues a trend of litigation partners leaving Big Law firms to open specialised boutiques, often driven by the desire for flexible billing and fewer conflicts of interest. Earlier this month, former Kirkland & Ellis partners Kent Hayden, Brendan Ryan and Zachary Ciullo launched Hayden Ryan & Ciullo in Chicago, telling law.com they saw opportunities to work on multimillion-dollar cases for clients that didn’t want to pay top Am Law rates “through a more focused and efficient platform”.
Last September, Brown Rudnick’s litigation co-chairs, Michael Bowe and Lauren Tabaksblat, left the firm to launch a boutique in New York focused on impact litigation, while earlier in the year, a raft of partners left Paul Weiss to join a new litigation shop in Washington DC founded in the wake of the firm’s deal with the White House to fend off a hostile executive order against it.
Email your news and story ideas to: [email protected]
