Investing in China has gone from red hot to ice cold in recent months. Is the weather changing again? Chinese portal SINA (NASDAQ:SINA) keeps growing wild. June quarter earnings more than doubled to $0.31 a share as revenues soared by 89%.

Along with rivals Sohu (NASDAQ:SOHU) and (NASDAQ:NTES), SINA saw its stock take off last year as a boom in mobile phone services and online ads fueled fat margins and profitability.

While all three may have hit a speed bump earlier this year as the finicky wireless crowd got stingy, the companies have broadened their revenue streams to keep future isolated hiccups in check.

Earlier this month, I argued in favor of the three Chinese portals on a valuation basis. With the stocks trading between 15 and 21 times this year's earnings -- and growing considerably faster than those levels -- I figured it was time to get excited about the sector again.

With the stocks continuing to trade at those levels, the argument remains. While there are other pure plays into the billion-resident strong China market like (NASDAQ:CTRP) and China Life Insurance (NYSE:LFC), the three portals are the ones that excite me the most, given their modest multiples and the upside of a country where more than 90% of its population is still offline. SINA is in the prime position as the country's leading portal. It's earned global recognition, particularly when Yahoo! (NASDAQ:YHOO) teamed up with the company earlier this year to open up an online auction site.

While SINA is looking at a third quarter that will be basically flat sequentially -- earning $0.29 to $0.30 a share on roughly $50 million in revenues -- it's still a big step from the $0.21 per share in profits on $31.7 million in revenues that it produced a year earlier. The implied net margins of 35% are also juicy on an absolute basis, even if they aren't as awesomely jaw-dropping as they had been earlier in the year.

So forget about those frothy days when SINA was a highflier. These days it's flying so low that you just might miss it on your investing radar.

Are you considering buying into the Chinese market? Are the political risks enough to scare you away, or are you more concerned with socioeconomic issues? All this and more in the China Connection discussion board. Only on

Longtime Fool contributor Rick Munarriz has been to China just once, but he sees huge potential there. However, he does not own shares in any of the companies mentioned in this story.