Tencent Holdings Limited (; ) is a Chinese investment holding company whose subsidiaries provide mass media, entertainment, Internet and mobile phone value-added services, and operate online advertising services in China. Its headquarters are in Nanshan District, Shenzhen. Tencent’s many services include social network, web portals, e-commerce, and multiplayer online games. Its offerings include the well-known (in China) instant messenger Tencent QQ and one of the largest web portals in China, QQ.com. Mobile chat service WeChat has helped bolster Tencent’s continued expansion into smartphone services. It is the fifth-largest Internet company in the world after Google, Amazon, Alibaba, and Ebay as of October 2014. In 2012, Tencent’s revenue outstripped Facebook’s by over $2 billion. In September 2013, Tencent’s market valuation rose to US$101 billion, nine years after going public. As March 12, 2014, the market value of Tencent is about 1.041 trillion yuan (US$150 billion).