First Manhattan Securities LLC

First Manhattan Securities LLC ("FMS") is a Delaware limited liability company headquartered at 399 Park Avenue, New York, NY. It is a registered broker-dealer with the SEC, a FINRA member, and a member of SIPC and the MSRB. Per its own financial statements and parent marketing materials, FMS is a wholly owned subsidiary of FMC Group Holdings LP, which does business as "First Manhattan" — an independent, partner-owned wealth management and advisory firm founded in 1964 by David "Sandy" Gottesman. (FMS's Rule 7.1 disclosure in the case below stated "No Corporate Parent"; the parent relationship is described in FMS's audited financial statement notes.)

Operations. FMS has a single line of business — securities brokerage — and reports as one operating segment. Its principal service is buying and selling securities for discretionary and non-discretionary accounts managed by its affiliate, the SEC-registered investment adviser First Manhattan Co. LLC, mostly for retail clients; it also serves limited non-discretionary brokerage accounts. Clearing, custody, and settlement are outsourced to Pershing LLC under a fully disclosed clearing agreement. FMS does not itself hold investment-adviser registration. The broader First Manhattan organization reported roughly $33–36 billion in client assets as of year-end 2024 and describes 145+ investment professionals; third-party databases estimate firm-wide headcount in the 100–200 range. FMS-specific headcount and revenue are not publicly disclosed and could not be verified.

Patent-litigation posture. FMS is a pure operating-company defendant: 0 plaintiff cases, 1 defendant case. That asymmetry, plus its regulated broker-dealer status, is consistent with a financial-services firm targeted by an outside patent asserter rather than an entity enforcing a portfolio.

Notable case. Cedar Lane Technologies Inc. v. First Manhattan Securities LLC, No. 1:25-cv-09485 (S.D.N.Y., filed Nov. 13, 2025), asserted U.S. Patent 8,577,782 ("Trading with conditional offers for semi-anonymous participants") against FMS's trading systems. Cedar Lane, a Canadian entity incorporated in 2019, is widely characterized as a patent assertion entity (Unified Patents; Stanford NPE Litigation Database) that has filed hundreds of suits, largely on patents acquired from Intellectual Ventures entities; its cases have historically clustered in the Western and Eastern Districts of Texas and Delaware. Here venue was S.D.N.Y. — where FMS is based. FMS's counsel was Fish & Richardson. The case terminated Dec. 30, 2025: all claims against FMS were dismissed with prejudice, and FMS's counterclaims were dismissed without prejudice.