Sean C. Knowles
- Firmwide Chair, Securities Litigation Practice
Sean handles securities litigation, corporate governance matters and litigation, and SEC enforcement investigations.
Sean Knowles represents public companies and their officers and directors in shareholder class action litigation, merger and acquisition litigation, U.S. Securities and Exchange Commission (SEC) enforcement proceedings and investigations, and shareholder derivative lawsuits. He also has defended clients against claims under the Washington State Securities Act and has counseled companies and their officers and directors on corporate governance matters.
Sean's experience includes defending clients against shareholder class actions alleging securities fraud in federal courts. He litigated securities matters regarding the mortgage-related financial crisis, including the consolidated multidistrict litigation In re Washington Mutual, Inc. Securities, Derivative & ERISA Litigation in the U.S. District Court for the Western District of Washington.
Experienced in SEC and state attorneys general investigations, as well as shareholder books and records inspection demands, Sean also handles Financial Industry Regulatory Authority inquiries and substantiation of confidentiality requests under the Freedom of Information Act. He has advised clients on Foreign Corrupt Practices Act compliance and related corporate governance issues.
Ranked as a leading lawyer in Chambers USA, he won praise from clients for his "work ethic, attention to detail, responsiveness, and upbeat attitude."
Education & Credentials
Education
- Columbia Law School, J.D., 1999
- Brown University, A.B., Psychology and Political Science, 1996
Bar and Court Admissions
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Washington
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New York
- U.S. Court of Appeals for the First Circuit
- U.S. Court of Appeals for the Ninth Circuit
- U.S. District Court for the Western District of Washington
- U.S. District Court for the Eastern District of Washington
Related Employment
- Bloomberg LP, Chicago, IL, Legal Analyst, 2007
- Davis Polk & Wardwell LLP, New York, NY, Litigation Associate, 1999-2006
- State of Rhode Island District Court, The Hon. Gilbert V. Indeglia, Providence, RI, Intern, 1996
Professional Recognition
Listed by Chambers USA as “America’s Leading Lawyers” for Litigation: General Commercial, 2023-2024
Listed in Best Lawyers in America: Litigation - Securities, 2016-2025
Insights
News
Professional Experience
Securities & Corporate Governance Litigation
Creative Solutions, Inc. Litigation
King County Superior Court (Washington)
Pierce County Superior Court (Washington)
Defend director against breach of fiduciary and related claims by purported shareholder.
Cocrystal Pharma, Inc. Securities and Derivative Litigation
U.S. District Court for the District of New Jersey
U.S. District Court for the Western District of Washington
Defend public company and current/former directors and officers in securities fraud class action and related shareholder derivative litigation concerning public disclosures and purported related party transaction.
Confidential Personal Counsel to Former Public Company Officer
U.S. District Court for the Western District of Washington
Serve as confidential personal counsel to former public company officer named as defendant in federal securities fraud class action litigation and related shareholder derivative litigation.
Confidential Personal Counsel to Former Public Company Director and Officers
U.S. District Court for the Northern District of Texas
Serve as confidential personal counsel to former public company director and officers named as defendants in federal securities fraud class action litigation and related shareholder derivative litigation.
FTE Networks Derivative Litigation
U.S. District Court for the Southern District of New York
Defend former public company chief operating officer in shareholder derivative litigation.
Papa Murphy’s Merger Litigation
U.S. District Court for the Western District of Washington
Defend public company and former officers and directors named as defendants in federal securities class action litigation alleging inadequate disclosures under Section 14(e) of the Securities Exchange Act of 1934.
Rocky Mountain Chocolate Factory Shareholder Meeting Litigation
Delaware Court of Chancery
Defend public company in shareholder litigation alleging failure to hold shareholder meeting in violation of Delaware General Corporation Code Section 211(c).
Celadon Securities and Derivative Litigation
U.S. District Court for the Southern District of New York
U.S. District Court for the Southern District of Indiana
Delaware Chancery Court
Defend former officers and director of public company named as defendants in federal securities fraud class action litigation and related shareholder derivative litigation.
Zillow Group, Inc. Securities and Derivative Litigation
U.S. District Court for the Western District of Washington
King County Superior Court (Washington)
Defend company and its officers and directors in securities fraud class action concerning co-marketing program and related shareholder derivative litigation.
Onvia, Inc. Merger Litigation
U.S. District Court for the Western District of Washington
King County Superior Court (Washington)
Defend company and its directors in shareholder class action challenging merger transaction.
Donuts, Inc. Merger Litigation
U.S. District Court for the Western District of Washington
Defend company in class action challenging merger transaction
Heritage Financial Corporation Merger Litigation
King County Superior Court (Washington)
Defend company in class action challenging merger transaction with Puget Sound Bancorp, Inc.
Costco Wholesale Corporation Derivative Litigation
King County Superior Court (Washington)
Defend company, officers and directors in shareholder derivative litigation.
Outerwall Tender Offer Litigation
U.S. District Court for the Western District of Washington
Represent Outerwall Inc. and its directors in shareholder class action challenging tender offer.
comScore Securities Litigation
U.S. District Court for the Southern District of New York
Represent Rentrak Corporation and its directors in shareholder class action challenging disclosures concerning merger transaction with comScore.
PIMCO Section 36(B) Litigation
U.S. District Court for the Western District of Washington
Defend claims charging that the PIMCO Total Return Fund charged disproportionately high management and other fees in violation of Section 36(b) of the Investment Company Act of 1940.
Teekay Corporation Securities Litigation
U.S. District Court for the Western District of Washington
Defend company and its CEO and CFO in securities fraud class action.
Cascade Microtech Merger Litigation
Circuit Court of Oregon, Multnomah County
Defend company and its directors in shareholder class action challenging merger transaction.
Planar Systems, Inc. Merger Litigation
Circuit Court of Oregon, Multnomah County
Defend company and its directors in shareholder class action challenging merger transaction.
Rentrak Corporation Merger Litigation
Circuit Court of Oregon, Multnomah County
Defend company and its directors in shareholder class action challenging merger transaction.
Weyerhaeuser Company Merger Litigation
King County Superior Court (Washington)
Defend company in class action challenging merger transaction with Plum Creek Timber Company.
TriQuint Merger Litigation
Circuit Court of Oregon, Multnomah County
Represent TriQuint (now Qorvo) and its directors in litigation arising from merger transaction with RF Micro Devices.
M/A-Com Technology Solutions Holdings, Inc. Merger Litigation
Superior Court of California, Orange County
Delaware Court of Chancery
Represent M/A-Com Technology Solutions Holdings, Inc. in litigation arising from its acquisition of Mindspeed Technologies, Inc.
Hipcricket Shareholder Litigation
King County Superior Court (Washington)
Defend Hipcricket, Inc. and its directors in shareholder litigation arising from asset purchase transaction.
Zillow Class C Stock Litigation
King County Superior Court (Washington)
Defend directors on Special Committee in shareholder class action challenging issuance of Class C non-voting stock.
Emeritus Corporation Merger Litigation
King County Superior Court (Washington)
Defend company and its directors in shareholder class action challenging merger transaction.
Heritage Financial Corporation Merger Litigation
King County Superior Court (Washington)
Defend company in class action challenging merger transaction with Washington Banking Company.
Penford Corporation Merger Litigation
King County Superior Court (Washington)
Defend company and its directors in shareholder class action challenging merger transaction.
Varolii Corp. v. Tiliacos, et al.
King County Superior Court (Washington)
Represent shareholders in dissenters' rights litigation arising from strategic transaction involving Varolii Corp.
Voyager Learning Company
U.S. District Court for the Eastern District of Michigan
Defend company in derivative lawsuits arising from accounting restatement.
Puget Sound Energy (PSE) Merger Litigation
King County Superior Court (Washington)
Defend PSE and its directors in shareholder class action challenging merger transaction.
Argent Classic Convertible Arbitrage Fund LP v. Countrywide Financial Corporation, et al.
U.S. District Court for the Central District of California
Defend corporate officer in securities class action litigation arising from collapse of country's largest mortgage lender.
Costco Wholesale Corporation Derivative Litigation
U.S. District Court for the Western District of Washington
Defend officers and directors in federal and state court derivative lawsuits.
Cardiac Science Corporation Merger Litigation (II)
Delaware Court of Chancery
Snohomish County Superior Court (Washington)
Defend company and its directors in class action challenging tender offer for Cardiac Science shares by Opto.
Captaris, Inc. Merger Litigation
King County Superior Court (Washington)
Defend company and its directors in shareholder class action challenging merger transaction.
Getty Images, Inc. Merger Litigation
King County Superior Court (Washington)
Defend Hellman & Friedman in class action merger litigation.
Itron, Inc. Derivative Litigation
Spokane County Superior Court (Washington)
Defend directors in shareholder derivative action.
Itron, Inc. Securities Litigation
U.S. District Court for the Eastern District of Washington
Defend company and its directors in securities fraud class action.
Knowledge Learning Corporation Securities Litigation
U.S. District Court for the Western District of Washington
Defend Knowledge Learning subsidiary for alleged securities violation arising from purchase of all assets of a company.
Washington Mutual, Inc. Securities, Derivative and ERISA Litigation
U.S. District Court for the Western District of Washington
King County Superior Court (Washington)
Defend outside directors of Washington Mutual, Inc. in multiple class action lawsuits arising from the collapse of WaMu.
Zillow, Inc. Securities and Derivative Litigation
U.S. District Court for the Western District of Washington
Defend company and its officers and directors in securities fraud class action and related derivative litigation.
Third-Party Witness Motion Practice
Represent former officer of Countrywide Financial Corporation in connection with motions to quash third-party deposition subpoenas in federal and state courts.
Market Leader Merger Litigation
King County Superior Court (Washington)
Defend company and its directors in shareholder class action merger litigation.
Public Company
Represent public company in connection with shareholder demand to inspect corporate records.
R.P. Martin Yen LIBOR Litigation
U.S. District Court for the Southern District of New York
Represent R.P. Martin Holdings Limited in Yen LIBOR litigation alleging violations of Commodity Exchange Act and Sherman Act.
Investigations & White Collar Defense
Private Technology Company
Represent private technology company in SEC enforcement investigation.
Private Financial Services Company
Represent private financial services company in internal investigation of potential employee misconduct.
Public Manufacturing Company
Represent public manufacturing company in internal investigation of potential employee misconduct.
SEC Enforcement Proceeding – Whistleblower Matter
Represent company in investigation arising from potential violation of Dodd-Frank Act whistleblower provision.
Public Company Short Swing Profit Matter
Represent company investigating potential violation of Section 16(b) of Securities and Exchange Act of 1934 by insider.
In the Matter of Countrywide Financial Corporation
Defend officer of Countrywide Financial Corporation in investigations of country's largest mortgage lender and related litigation.
Public Company
Represent public company in FINRA trading review relating to company's announcement of entry into a definitive merger agreement.
Fortune 100 Company
Represent Fortune 100 company in connection with investigation and overseas criminal prosecution of alleged accounting irregularities by subsidiary.
Fortune 200 Manufacturing Company
Defend Fortune 200 manufacturing company in SEC enforcement investigation of accounting matters.
Fortune 500 Company SEC Enforcement Investigation
Defend Fortune 500 company in SEC enforcement investigation of goodwill accounting issue.
State of Washington v. Asurion, LLC, et al.
Defend company in investigation by Washington State Attorney General of alleged misconduct in connection with sales of cellular phone services.
Other Litigation
Prima Technology, Inc. v. Alux Inc., et al.
Snohomish County Superior Court (Washington)
Represent company in litigation against former officers for alleged diversion of assets.