Zhou Hongyi

Zhou Hongyi — founder profiled in the Chinese Founder Ledger — is documented as follows: xi'an Jiaotong University-trained entrepreneur who founded search-keyword company 3721 in 1998, sold it to Yahoo! in 2004 for $120 million, then left after management disagreements to found internet-security company Qihoo 360. The profile is grounded in the 1 sources indexed for this founder.

Zhou Hongyi's role is documented as: co-founder, Chairman and CEO, Qihoo 360 Wikipedia lists Zhou as co-founder, chairman and CEO of Qihoo 360 with an accompanying 2025 photo, suggesting the role was current as of that year; no more recent primary source was fetched in this pass (research date: 2026-08-23).

Zhou founded 3721 in 1998, a search engine that sold Chinese-language keywords for Roman-alphabet domain names, an early and distinctly China-specific internet business model.

China's operations, but differences between Zhou and Yahoo's management led Yahoo to sell its China operations to Alibaba in 2005, after which Zhou departed to start Qihoo 360.

As of November 2018, Forbes ranked Zhou #45 on its China Rich List and #135 on its global Billionaires list, with an estimated net worth of $4.7 billion.

Left Yahoo! China after management disagreements and founded Qihoo 360 following Yahoo's 2005 sale of its China operations to Alibaba.

Qihoo 360 grew into a major Chinese internet-security company, with Zhou continuing as co-founder, chairman and CEO.