RPX Corporation

RPX Corporation, short for Rational Patent Exchange, is an American provider of international patent risk management services headquartered in San Francisco, California, founded in March 2008 by John A. Amster, Geoffrey T. Barker, Eran Zur, and Steven Waterhouse. It operates in defensive patent aggregation, acquiring patents that could otherwise be used offensively against its member companies to help them limit litigation risk from non practicing entities, and reported revenue of 330.4 million dollars in 2017 with about 125 employees. RPX traded on Nasdaq as RPXC from 2011 until private equity firm HGGC acquired the company in 2018, after which it continued providing defensive patent services and data analytics to member companies as a private company. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/