Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of SINA Corp. (NASDAQ:SINA)fell more than 10% during Tuesday's intraday trading, even after the Chinese Internet media company reported slightly better-than-expected fourth quarter results and inline forward revenue guidance.

So what: Adjusted net revenue rose 43% year over year to $192.3 million, which translated to a 267% gain in non-GAAP net income to $0.47 per diluted share. Analysts, on average, were looking for adjusted earnings of only $0.46 per share on sales of $191.69 million.

SINA also provided guidance for adjusted first quarter sales between $162 million and $167 million, which is inline with expectations for Q1 sales of $164.67 million.

Now what: After crediting SINA's Q4 strength to the performance of Weibo's advertising and value-added services, CEO Charles Chao weighed in, "As we enter 2014, we will continue to focus on growing Weibo's user base and user engagement through product innovation, as well as seizing opportunities to enable us for long term growth."  

During SINA's subsequent conference call, however, Chao elaborated that Weibo's December average daily active users increased just 4.2% from September to 61.4 million, compared to an 11.2% gain from June to September.

This in mind, a Wall Street Journal report today stated SINA could be planning a $500 million second-quarter IPO of Weibo, which has faced political pressure in the past after the Chinese government launched an "antirumor campaign" aimed at stemming the influence of such services. In the end, given the uncertainty surrounding the future of SINA's promising platform, it's hard to blame SINA shareholders for taking a step back today.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.