When Fortune 500 companies, financial institutions, and high net-worth individuals face complex financial disputes, Stephen Ascher relentlessly pursues their goals. Stephen is a first-chair trial lawyer, regularly representing both plaintiffs and defendants. His clients gain better advice thanks to his extensive experience on both sides of the “v.”

Co-Chair of Jenner & Block’s Investor and Securities Litigation Practice, Stephen began his career as a white-collar criminal defense lawyer at a small firm where he learned to think strategically and creatively, addressing an unusually broad variety of situations and challenges. He gains a deep understanding of his clients’ businesses, enabling him to communicate with companies in their industry-specific language, and then simplify and explain these concepts to judges, arbitrators, and juries. Using keen quantitative skills, Stephen is particularly effective when cross-examining traders, accountants, and other witnesses with technical expertise.

Stephen takes on the big cases with extraordinary complexity and sophistication. While representing a major asset manager in a dispute with AIG concerning interest rate swaps, he led one of the largest solvency analyses in history, helping to secure a $600 million gain for the client. He has led numerous teams in matters where his client achieved a 9-digit recovery. For defendants, he has frequently developed novel defenses that resulted in dismissals.

Litigation requires a rare combination of aggression and judgment. Aggression, to pursue arguments and avenues relentlessly. And the judgment to know which are the most likely to be successful.

Representative Matters

  • Leading the representation of Microsoft and Activision in highly publicized breach of fiduciary duty litigation arising out of Microsoft’s $70 billion acquisition of Activision.
  • Tried a theft of trade secrets claim against a Fortune 500 pharma company on behalf of a major biotech company. After a 3-week trial, proved that client trade secrets had been misappropriated.
  • Represented institutional investors in numerous claims arising out of “built to fail” CDOs after the 2008 financial crisis. Clients recovered hundreds of millions of dollars in settlements.
  • Successfully guided one of the largest cannabis companies in the United States in several arbitrations and lawsuits related to dealings with minority investors and their securities offerings.
  • Represented several world-class hedge funds and trading firms in nine-figure disputes concerning derivatives, structured finance transactions, and trade secrets.
  • Represented major real estate companies in disputes with other market participants and borrowers.
  • Regularly represents Fortune 500 and other significant companies in securities litigation.

Credentials

  • New York, 1993

  • Harvard Law School, JD, cum laude, 1991
  • Harvard College, BA, magna cum laude, 1988

  • US Supreme Court, 2000
  • US Court of Appeals, Second Circuit, 2005
  • US Court of Appeals, Eleventh Circuit, 2004
  • US District Court, Eastern District of New York, 1993
  • US District Court, Southern District of New York, 1993

  • Hon. Jesse E. Eschbach, US Court of Appeals, Seventh Circuit, 1991-1992

Service / Recognition

  • Chambers USA, Litigation: Securities (New York), 2021-2025
  • New York Metro Super Lawyers, 2008-2022, in Securities Litigation, Criminal Defense: White Collar, and General Litigation.
  • Legal 500, Dispute Resolution, Securities Litigation - Defense, 2016-2021; Cannabis, 2021
  • Leaders League, Litigation & Competition Directory, Securities Litigation, 2018
  • The Best Lawyers in America, Litigation-Banking and Finance, 2026

  • American Bar Association, Securities Litigation Committee, Member
  • Association of the Bar of the City of New York, Member
  • New York State Bar Association, White-Collar Criminal Defense Committee, Member, 2007-2010
  • New York State Bar Association, Hedge Fund and Capital Markets Litigation, Co-Chair, 2013

When Fortune 500 companies, financial institutions, and high net-worth individuals face complex financial disputes, Stephen Ascher relentlessly pursues their goals. Stephen is a first-chair trial lawyer, regularly representing both plaintiffs and defendants. His clients gain better advice thanks to his extensive experience on both sides of the “v.”

Co-Chair of Jenner & Block’s Investor and Securities Litigation Practice, Stephen began his career as a white-collar criminal defense lawyer at a small firm where he learned to think strategically and creatively, addressing an unusually broad variety of situations and challenges. He gains a deep understanding of his clients’ businesses, enabling him to communicate with companies in their industry-specific language, and then simplify and explain these concepts to judges, arbitrators, and juries. Using keen quantitative skills, Stephen is particularly effective when cross-examining traders, accountants, and other witnesses with technical expertise.

Stephen takes on the big cases with extraordinary complexity and sophistication. While representing a major asset manager in a dispute with AIG concerning interest rate swaps, he led one of the largest solvency analyses in history, helping to secure a $600 million gain for the client. He has led numerous teams in matters where his client achieved a 9-digit recovery. For defendants, he has frequently developed novel defenses that resulted in dismissals.

Litigation requires a rare combination of aggression and judgment. Aggression, to pursue arguments and avenues relentlessly. And the judgment to know which are the most likely to be successful.

  • Leading the representation of Microsoft and Activision in highly publicized breach of fiduciary duty litigation arising out of Microsoft’s $70 billion acquisition of Activision.
  • Tried a theft of trade secrets claim against a Fortune 500 pharma company on behalf of a major biotech company. After a 3-week trial, proved that client trade secrets had been misappropriated.
  • Represented institutional investors in numerous claims arising out of “built to fail” CDOs after the 2008 financial crisis. Clients recovered hundreds of millions of dollars in settlements.
  • Successfully guided one of the largest cannabis companies in the United States in several arbitrations and lawsuits related to dealings with minority investors and their securities offerings.
  • Represented several world-class hedge funds and trading firms in nine-figure disputes concerning derivatives, structured finance transactions, and trade secrets.
  • Represented major real estate companies in disputes with other market participants and borrowers.
  • Regularly represents Fortune 500 and other significant companies in securities litigation.

  • New York, 1993

  • Harvard Law School, JD, cum laude, 1991
  • Harvard College, BA, magna cum laude, 1988

  • US Supreme Court, 2000
  • US Court of Appeals, Second Circuit, 2005
  • US Court of Appeals, Eleventh Circuit, 2004
  • US District Court, Eastern District of New York, 1993
  • US District Court, Southern District of New York, 1993

  • Hon. Jesse E. Eschbach, US Court of Appeals, Seventh Circuit, 1991-1992

  • Chambers USA, Litigation: Securities (New York), 2021-2025
  • New York Metro Super Lawyers, 2008-2022, in Securities Litigation, Criminal Defense: White Collar, and General Litigation.
  • Legal 500, Dispute Resolution, Securities Litigation - Defense, 2016-2021; Cannabis, 2021
  • Leaders League, Litigation & Competition Directory, Securities Litigation, 2018
  • The Best Lawyers in America, Litigation-Banking and Finance, 2026

  • American Bar Association, Securities Litigation Committee, Member
  • Association of the Bar of the City of New York, Member
  • New York State Bar Association, White-Collar Criminal Defense Committee, Member, 2007-2010
  • New York State Bar Association, Hedge Fund and Capital Markets Litigation, Co-Chair, 2013

Overview

When Fortune 500 companies, financial institutions, and high net-worth individuals face complex financial disputes, Stephen Ascher relentlessly pursues their goals. Stephen is a first-chair trial lawyer, regularly representing both plaintiffs and defendants. His clients gain better advice thanks to his extensive experience on both sides of the “v.”

Co-Chair of Jenner & Block’s Investor and Securities Litigation Practice, Stephen began his career as a white-collar criminal defense lawyer at a small firm where he learned to think strategically and creatively, addressing an unusually broad variety of situations and challenges. He gains a deep understanding of his clients’ businesses, enabling him to communicate with companies in their industry-specific language, and then simplify and explain these concepts to judges, arbitrators, and juries. Using keen quantitative skills, Stephen is particularly effective when cross-examining traders, accountants, and other witnesses with technical expertise.

Stephen takes on the big cases with extraordinary complexity and sophistication. While representing a major asset manager in a dispute with AIG concerning interest rate swaps, he led one of the largest solvency analyses in history, helping to secure a $600 million gain for the client. He has led numerous teams in matters where his client achieved a 9-digit recovery. For defendants, he has frequently developed novel defenses that resulted in dismissals.

Litigation requires a rare combination of aggression and judgment. Aggression, to pursue arguments and avenues relentlessly. And the judgment to know which are the most likely to be successful.

Representative Matters

  • Leading the representation of Microsoft and Activision in highly publicized breach of fiduciary duty litigation arising out of Microsoft’s $70 billion acquisition of Activision.
  • Tried a theft of trade secrets claim against a Fortune 500 pharma company on behalf of a major biotech company. After a 3-week trial, proved that client trade secrets had been misappropriated.
  • Represented institutional investors in numerous claims arising out of “built to fail” CDOs after the 2008 financial crisis. Clients recovered hundreds of millions of dollars in settlements.
  • Successfully guided one of the largest cannabis companies in the United States in several arbitrations and lawsuits related to dealings with minority investors and their securities offerings.
  • Represented several world-class hedge funds and trading firms in nine-figure disputes concerning derivatives, structured finance transactions, and trade secrets.
  • Represented major real estate companies in disputes with other market participants and borrowers.
  • Regularly represents Fortune 500 and other significant companies in securities litigation.

Credentials

Admissions

  • New York, 1993

Education

  • Harvard Law School, JD, cum laude, 1991
  • Harvard College, BA, magna cum laude, 1988

Court Admissions

  • US Supreme Court, 2000
  • US Court of Appeals, Second Circuit, 2005
  • US Court of Appeals, Eleventh Circuit, 2004
  • US District Court, Eastern District of New York, 1993
  • US District Court, Southern District of New York, 1993

Clerkships

  • Hon. Jesse E. Eschbach, US Court of Appeals, Seventh Circuit, 1991-1992

Service / Recognition

Awards

  • Chambers USA, Litigation: Securities (New York), 2021-2025
  • New York Metro Super Lawyers, 2008-2022, in Securities Litigation, Criminal Defense: White Collar, and General Litigation.
  • Legal 500, Dispute Resolution, Securities Litigation - Defense, 2016-2021; Cannabis, 2021
  • Leaders League, Litigation & Competition Directory, Securities Litigation, 2018
  • The Best Lawyers in America, Litigation-Banking and Finance, 2026

Service to the Bar

  • American Bar Association, Securities Litigation Committee, Member
  • Association of the Bar of the City of New York, Member
  • New York State Bar Association, White-Collar Criminal Defense Committee, Member, 2007-2010
  • New York State Bar Association, Hedge Fund and Capital Markets Litigation, Co-Chair, 2013

When Fortune 500 companies, financial institutions, and high net-worth individuals face complex financial disputes, Stephen Ascher relentlessly pursues their goals. Stephen is a first-chair trial lawyer, regularly representing both plaintiffs and defendants. His clients gain better advice thanks to his extensive experience on both sides of the “v.”

Co-Chair of Jenner & Block’s Investor and Securities Litigation Practice, Stephen began his career as a white-collar criminal defense lawyer at a small firm where he learned to think strategically and creatively, addressing an unusually broad variety of situations and challenges. He gains a deep understanding of his clients’ businesses, enabling him to communicate with companies in their industry-specific language, and then simplify and explain these concepts to judges, arbitrators, and juries. Using keen quantitative skills, Stephen is particularly effective when cross-examining traders, accountants, and other witnesses with technical expertise.

Stephen takes on the big cases with extraordinary complexity and sophistication. While representing a major asset manager in a dispute with AIG concerning interest rate swaps, he led one of the largest solvency analyses in history, helping to secure a $600 million gain for the client. He has led numerous teams in matters where his client achieved a 9-digit recovery. For defendants, he has frequently developed novel defenses that resulted in dismissals.

Litigation requires a rare combination of aggression and judgment. Aggression, to pursue arguments and avenues relentlessly. And the judgment to know which are the most likely to be successful.

Representative Matters

  • Leading the representation of Microsoft and Activision in highly publicized breach of fiduciary duty litigation arising out of Microsoft’s $70 billion acquisition of Activision.
  • Tried a theft of trade secrets claim against a Fortune 500 pharma company on behalf of a major biotech company. After a 3-week trial, proved that client trade secrets had been misappropriated.
  • Represented institutional investors in numerous claims arising out of “built to fail” CDOs after the 2008 financial crisis. Clients recovered hundreds of millions of dollars in settlements.
  • Successfully guided one of the largest cannabis companies in the United States in several arbitrations and lawsuits related to dealings with minority investors and their securities offerings.
  • Represented several world-class hedge funds and trading firms in nine-figure disputes concerning derivatives, structured finance transactions, and trade secrets.
  • Represented major real estate companies in disputes with other market participants and borrowers.
  • Regularly represents Fortune 500 and other significant companies in securities litigation.

Credentials

  • New York, 1993

  • Harvard Law School, JD, cum laude, 1991
  • Harvard College, BA, magna cum laude, 1988

  • US Supreme Court, 2000
  • US Court of Appeals, Second Circuit, 2005
  • US Court of Appeals, Eleventh Circuit, 2004
  • US District Court, Eastern District of New York, 1993
  • US District Court, Southern District of New York, 1993

  • Hon. Jesse E. Eschbach, US Court of Appeals, Seventh Circuit, 1991-1992

Service / Recognition

  • Chambers USA, Litigation: Securities (New York), 2021-2025
  • New York Metro Super Lawyers, 2008-2022, in Securities Litigation, Criminal Defense: White Collar, and General Litigation.
  • Legal 500, Dispute Resolution, Securities Litigation - Defense, 2016-2021; Cannabis, 2021
  • Leaders League, Litigation & Competition Directory, Securities Litigation, 2018
  • The Best Lawyers in America, Litigation-Banking and Finance, 2026

  • American Bar Association, Securities Litigation Committee, Member
  • Association of the Bar of the City of New York, Member
  • New York State Bar Association, White-Collar Criminal Defense Committee, Member, 2007-2010
  • New York State Bar Association, Hedge Fund and Capital Markets Litigation, Co-Chair, 2013

When Fortune 500 companies, financial institutions, and high net-worth individuals face complex financial disputes, Stephen Ascher relentlessly pursues their goals. Stephen is a first-chair trial lawyer, regularly representing both plaintiffs and defendants. His clients gain better advice thanks to his extensive experience on both sides of the “v.”

Co-Chair of Jenner & Block’s Investor and Securities Litigation Practice, Stephen began his career as a white-collar criminal defense lawyer at a small firm where he learned to think strategically and creatively, addressing an unusually broad variety of situations and challenges. He gains a deep understanding of his clients’ businesses, enabling him to communicate with companies in their industry-specific language, and then simplify and explain these concepts to judges, arbitrators, and juries. Using keen quantitative skills, Stephen is particularly effective when cross-examining traders, accountants, and other witnesses with technical expertise.

Stephen takes on the big cases with extraordinary complexity and sophistication. While representing a major asset manager in a dispute with AIG concerning interest rate swaps, he led one of the largest solvency analyses in history, helping to secure a $600 million gain for the client. He has led numerous teams in matters where his client achieved a 9-digit recovery. For defendants, he has frequently developed novel defenses that resulted in dismissals.

Litigation requires a rare combination of aggression and judgment. Aggression, to pursue arguments and avenues relentlessly. And the judgment to know which are the most likely to be successful.

  • Leading the representation of Microsoft and Activision in highly publicized breach of fiduciary duty litigation arising out of Microsoft’s $70 billion acquisition of Activision.
  • Tried a theft of trade secrets claim against a Fortune 500 pharma company on behalf of a major biotech company. After a 3-week trial, proved that client trade secrets had been misappropriated.
  • Represented institutional investors in numerous claims arising out of “built to fail” CDOs after the 2008 financial crisis. Clients recovered hundreds of millions of dollars in settlements.
  • Successfully guided one of the largest cannabis companies in the United States in several arbitrations and lawsuits related to dealings with minority investors and their securities offerings.
  • Represented several world-class hedge funds and trading firms in nine-figure disputes concerning derivatives, structured finance transactions, and trade secrets.
  • Represented major real estate companies in disputes with other market participants and borrowers.
  • Regularly represents Fortune 500 and other significant companies in securities litigation.

  • New York, 1993

  • Harvard Law School, JD, cum laude, 1991
  • Harvard College, BA, magna cum laude, 1988

  • US Supreme Court, 2000
  • US Court of Appeals, Second Circuit, 2005
  • US Court of Appeals, Eleventh Circuit, 2004
  • US District Court, Eastern District of New York, 1993
  • US District Court, Southern District of New York, 1993

  • Hon. Jesse E. Eschbach, US Court of Appeals, Seventh Circuit, 1991-1992

  • Chambers USA, Litigation: Securities (New York), 2021-2025
  • New York Metro Super Lawyers, 2008-2022, in Securities Litigation, Criminal Defense: White Collar, and General Litigation.
  • Legal 500, Dispute Resolution, Securities Litigation - Defense, 2016-2021; Cannabis, 2021
  • Leaders League, Litigation & Competition Directory, Securities Litigation, 2018
  • The Best Lawyers in America, Litigation-Banking and Finance, 2026

  • American Bar Association, Securities Litigation Committee, Member
  • Association of the Bar of the City of New York, Member
  • New York State Bar Association, White-Collar Criminal Defense Committee, Member, 2007-2010
  • New York State Bar Association, Hedge Fund and Capital Markets Litigation, Co-Chair, 2013

Overview

When Fortune 500 companies, financial institutions, and high net-worth individuals face complex financial disputes, Stephen Ascher relentlessly pursues their goals. Stephen is a first-chair trial lawyer, regularly representing both plaintiffs and defendants. His clients gain better advice thanks to his extensive experience on both sides of the “v.”

Co-Chair of Jenner & Block’s Investor and Securities Litigation Practice, Stephen began his career as a white-collar criminal defense lawyer at a small firm where he learned to think strategically and creatively, addressing an unusually broad variety of situations and challenges. He gains a deep understanding of his clients’ businesses, enabling him to communicate with companies in their industry-specific language, and then simplify and explain these concepts to judges, arbitrators, and juries. Using keen quantitative skills, Stephen is particularly effective when cross-examining traders, accountants, and other witnesses with technical expertise.

Stephen takes on the big cases with extraordinary complexity and sophistication. While representing a major asset manager in a dispute with AIG concerning interest rate swaps, he led one of the largest solvency analyses in history, helping to secure a $600 million gain for the client. He has led numerous teams in matters where his client achieved a 9-digit recovery. For defendants, he has frequently developed novel defenses that resulted in dismissals.

Litigation requires a rare combination of aggression and judgment. Aggression, to pursue arguments and avenues relentlessly. And the judgment to know which are the most likely to be successful.

Representative Matters

  • Leading the representation of Microsoft and Activision in highly publicized breach of fiduciary duty litigation arising out of Microsoft’s $70 billion acquisition of Activision.
  • Tried a theft of trade secrets claim against a Fortune 500 pharma company on behalf of a major biotech company. After a 3-week trial, proved that client trade secrets had been misappropriated.
  • Represented institutional investors in numerous claims arising out of “built to fail” CDOs after the 2008 financial crisis. Clients recovered hundreds of millions of dollars in settlements.
  • Successfully guided one of the largest cannabis companies in the United States in several arbitrations and lawsuits related to dealings with minority investors and their securities offerings.
  • Represented several world-class hedge funds and trading firms in nine-figure disputes concerning derivatives, structured finance transactions, and trade secrets.
  • Represented major real estate companies in disputes with other market participants and borrowers.
  • Regularly represents Fortune 500 and other significant companies in securities litigation.

Credentials

Admissions

  • New York, 1993

Education

  • Harvard Law School, JD, cum laude, 1991
  • Harvard College, BA, magna cum laude, 1988

Court Admissions

  • US Supreme Court, 2000
  • US Court of Appeals, Second Circuit, 2005
  • US Court of Appeals, Eleventh Circuit, 2004
  • US District Court, Eastern District of New York, 1993
  • US District Court, Southern District of New York, 1993

Clerkships

  • Hon. Jesse E. Eschbach, US Court of Appeals, Seventh Circuit, 1991-1992

Service / Recognition

Awards

  • Chambers USA, Litigation: Securities (New York), 2021-2025
  • New York Metro Super Lawyers, 2008-2022, in Securities Litigation, Criminal Defense: White Collar, and General Litigation.
  • Legal 500, Dispute Resolution, Securities Litigation - Defense, 2016-2021; Cannabis, 2021
  • Leaders League, Litigation & Competition Directory, Securities Litigation, 2018
  • The Best Lawyers in America, Litigation-Banking and Finance, 2026

Service to the Bar

  • American Bar Association, Securities Litigation Committee, Member
  • Association of the Bar of the City of New York, Member
  • New York State Bar Association, White-Collar Criminal Defense Committee, Member, 2007-2010
  • New York State Bar Association, Hedge Fund and Capital Markets Litigation, Co-Chair, 2013

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