Sina Corporation launched Sina Weibo on August 14 , 2009 .
As of Q4 2017 , Sina Weibo has over 392 million monthly active users , with surging stocks , advertising sales , revenue and total earnings in the quarter. < /ref > In March 2014 , Sina Corporation announced a spinoff of Weibo as a separate entity and filed an IPO under the symbol WB .
Sina Weibo