(1) Study NPE
Studying NPE, such as ordinary universities, colleges and research laboratories, usually carries out basic research, and then licenses inventions without producing products after applying for patents.
(2) Speculative NPE
Speculative NPE refers to individuals and small groups who buy patents, and they use the purchased patents to deal with successful products in the market. The activities of such companies are usually denounced by the operating companies, who think that their actions are tantamount to extortion, relying on their patents to extract profits far higher than the actual added value of products and hinder innovation. Because such companies don't manufacture products, they can't let their opponents file counterclaims of infringement or cross-licensing. Others call them "patent hooligans", that is, "patent hooligans".
(3) Defensive NPE
Like speculative NPE, defensive NPE also buys patents, but it is mainly a defense-oriented company aimed at fighting speculative NPE. Similarly, because these companies don't manufacture products, speculative NPE can't file infringement lawsuits or cross-licenses.