market folly

John Thaler's hedge fund JAT Capital has been buying shares of Sina Corp (SINA) hand over fist. Per a 13G filed with the SEC, the hedge fund has disclosed a 5.6% ownership stake in SINA with 3,384,385 shares.

JAT has doubled its position and then some in the past few weeks as they only owned 1,455,995 shares at the end of March. And before that at the end of December, they only held 513,920 shares. Over the past six months, JAT Capital has ramped up its position by almost 560%.

Social Media Investing Boom

Sina Corp is at the crossroads of two hot investing trends: social media and China. SINA is essentially the 'Twitter of China' and with the recent LinkedIn (LNKD) IPO, the social media investing boom is here. By the way, don't forget to follow @marketfolly on Twitter for intra-day commentary and further hedge fund coverage.

Per Google Finance, Sina Corp is "an online media company and MVAS provider in the People’s Republic of China (PRC) and the global Chinese communities. The Company provides services through five business lines, including SINA.com (online news and content), SINA Mobile (MVAS), SINA Community (Web 2.0 and social networking-based services and games), SINA.net (search and enterprise services), and SINA E-Commerce (online shopping)."

About John Thaler/JAT Capital

Before founding JAT Capital in 2007, Thaler worked at Shumway Capital Partners where he was responsible for covering technology, media and telecom and he managed the internal Omni fund. Prior to that, he worked in private equity at Spectrum Equity Investors.

Due to this experience, it should come as no surprise that Thaler employs a fundamental research process and private equity-like approach to investing with an emphasis on tech. Thaler earned his BA in Economics from the University of Chicago.

In 2008, JAT returned -5.9% (compared to -37% for the S&P) and in 2009, Thaler's fund returned 23.2% gross.