M. Elizabeth Day

Specialty / focus. M. Elizabeth Day is a Silicon Valley patent trial lawyer with roughly 30 years' experience in high-technology disputes. Practice descriptions and rankings (IAM Patent 1000, Chambers USA) place her work across semiconductor packaging, Wi-Fi and cellular communications, smartphones, flash memory, computer security/networking, data compression, interactive television, and content delivery. She has tried more than a dozen cases as first or second chair and is specifically known for handling damages and IP monetization strategy. Her two tracked matters reflect that profile: Intellectual Ventures I LLC v. Capital One Financial Corp. (financial/banking software patents) and Adeia Media Holdings Inc. v. DirecTV, LLC (filed July 2026 in C.D. Cal., involving Adeia's streaming/media technology portfolio).

Side preference. Day's tracked appearances are 2–0 plaintiff-side, and she currently works almost exclusively for patent owners — both Intellectual Ventures and Adeia are patent-licensing/NPE-side entities. IAM describes her as playing a "central role in monetisation strategies" for patent holders, and her firm, Bunsow De Mory, is itself a plaintiff-side IP boutique. Early in her career she also defended operating companies (e.g., representing Equinox Payments), and her own bios note first-chair work for both plaintiffs and defendants, but the recent practice is clearly patent-owner oriented.

Firm context. Day is a partner at Bunsow De Mory LLP (Redwood City, CA), which she joined after co-founding Feinberg Day Alberti & Thompson LLP in 2011 (later Feinberg Day Kramer Alberti Lim Tonkovich & Belloli), a boutique launched with Ian Feinberg and other former DLA Piper lawyers. Before that she was a partner in DLA Piper's IP litigation group, and earlier at Gray Cary Ware & Freidenrich. She is ranked by Chambers (Band 5, IP: Patent Litigation – California) and IAM Patent 1000, and recognized by Benchmark Litigation as a Litigation Star.

Notable cases / outcomes. Intellectual Ventures v. Capital One is the most prominent tracked matter: it produced a leading post-Alice Federal Circuit decision, 792 F.3d 1363 (Fed. Cir. 2015), affirming § 101 invalidation of IV's asserted claims — an adverse result for her client but a significant eligibility ruling. More recently, per IAM and firm materials, Day built the damages case for TOT Power Control against Apple that yielded a $110M+ jury verdict in 2025, and she secured a pre-trial settlement for VideoLabs against Dell. (These are drawn from ranking profiles and firm announcements, not independently verified court records.) Her practice also extends to the ITC.

PTAB / IPR; bar / education. I found no evidence that Day appears regularly in IPR/PGR proceedings; her tracked practice and public profiles emphasize district court, ITC, and Federal Circuit work, although her firm advertises a top-ranked PTAB practice. Admitted to the California bar in 1995, including the Northern, Central, and Eastern Districts of California and the Ninth and Federal Circuits. She holds a BA from Dartmouth College (1991) and a JD/MBA from UC Davis (1994).