Sina Weibo is a Chinese microblogging website launched in 2009 that had over 500 million registered users and 61 million daily active users as of 2013. It filed for a $500 million US IPO in March 2014, giving it a valuation between $3.3-7 billion. While it grew rapidly after its 2009 launch and a user surpassed 100 million by 2011, it has faced increasing competition from other social media like WeChat in recent years.