Chinese tech company SINA (NASDAQ:SINA) is often overshadowed by bigger players like Baidu (NASDAQ:BIDU), Alibaba (NYSE:BABA), and Tencent (OTC:TCEHY). But since going public in 2000 at $17 per share, the stock rose nearly 530% to its current price.

This means that if you had invested $160,000 in SINA's IPO, your initial investment would be worth over $1 million today. If you had bought SINA after it sank to nearly $1 per share in late 2001, an investment of just $10,000 would be worth $1 million today.

A group of young people take a selfie.

Source: Getty Images.

But as all investors should know, past performance never guarantees future returns. So can buying SINA today still make you a millionaire over the next few years? Let's examine its core business, challenges, and valuations to find out.

Understanding SINA's business

SINA generates revenue from its social network Weibo (NASDAQ:WB) and various portal websites, which cover the news, entertainment, sports, business, and other topics on PCs and mobile devices.

SINA spun off Weibo as a publicly traded company in 2014, but still retains a 46% stake in the company, which gives it a 72% voting share. Alibaba is Weibo's second largest stakeholder -- which has constantly fueled speculation that the e-commerce giant could buy SINA or Weibo to widen its moat against Tencent's WeChat.

Weibo's mobile app.

Weibo's mobile app. Source: Google Play.

SINA's total revenue grew 47% annually to $358.9 million last quarter. Revenues from Weibo rose 72%, fueled by a big jump in advertising revenues, and accounted for 71% of SINA's top line. The rest of SINA's revenue came from its older portal business, which posted 9% growth.

Profitability has been improving at both businesses. Weibo's gross margin expanded from 72% a year ago to 80%, while the portal unit's gross margin jumped from 51% to 61%. Its total gross margin rose from 64% to 74%, which lifted its non-GAAP net income by 165% to $52.7 million.

Understanding the tailwinds and headwinds

SINA's biggest tailwind is Weibo, which grew its monthly active users (MAUs) by 28% annually to 361 million last quarter. Weibo is the preferred communication tool for Chinese celebrities, who lure millions of followers to its ecosystem.

Weibo is often called the "Chinese Twitter", but it actually blends aspects of Twitter's tweets, Facebook's core social network, and Reddit's forum-based conversations in a jack of all trades ecosystem. Analysts expect Weibo's revenue and earnings to respectively rise 66% and 99% this year -- so SINA is an easy way to profit from its growth.

An Asian traveler takes a selfie with her smartphone.

Source: Getty Images.

Analysts expect SINA's growth -- throttled by its portal business -- to be slightly less impressive than Weibo's with 46% sales growth and 99% earnings growth this year. But SINA's P/E of 35 is also much lower than Weibo's P/E of 120, and compares favorably to the industry average of 37 for internet information providers. This arguably makes SINA a safer play on Weibo than Weibo itself.

Yet SINA and Weibo both remain vulnerable to government crackdowns. Chinese regulators threatened to shut down SINA's portals in 2015, claiming that they "distorted news facts, violated morality, and engaged in media hype." Earlier this year, regulators forced Weibo to suspend all live audio and video broadcasts on its site, claiming that the company hadn't obtained a new government broadcasting license. These incidents indicate that SINA and Weibo need to tread very carefully to maintain their double-digit growth rates.

But can SINA become a multibagger again?

SINA has great growth potential, but I wouldn't call it a potential multibagger at current prices. Both SINA and Weibo's growth could eventually peak as their platforms bump up against Tencent and Baidu's growing ecosystems.

Alibaba might try to buy SINA or Weibo, and SINA's price and valuation could rise to more accurately reflect Weibo's growth. But neither catalyst should make the stock double or triple over the next few years. Nonetheless, I still believe that SINA is a solid, oft-overlooked play on rising internet penetration rates in China and the growth of the country's middle class.