China’s largest search engine Baidu(BIDU) opened lowered and plunged 5.74% to close at $98.6 Wednesday, the first time falling below the $100 since January, 2011, weighed down by worries over monetization of its mobile business, analysts said.

The shares went to a 52-week low of $98.35 during the day while the daily trading volume expanded to 10.35million from an average of 4.54million.

Mobile search represent an insignificant part of the company’s total revenue at this stage.

The company has done a lot of things and is trying all kinds of different techniques to help educate customers about mobile search, said CEO Robin Li at Baidu’s third quarter 2012 earnings conference call.

“We're also working hard to close the mobile monetization gap, although this will inevitably involve a period of transition,” he said.

The Chinese search provider continued steady growth in profits in the third quarter, with a 49.7 percent jump in revenues year over year to $994.6 million, a 48.1 percent increase in profit year over year to $524.6 million and $1.37 in earnings per share for the period, according to its earnings results for Q3 released in October.

 “Mobile and cloud represent our vision for the future of China’s Internet, and Baidu will continue to proactively drive the development of this crucial ecosystem. We stand ready to meet the challenges and capture the opportunities the PC-to-mobile transition presents,” CEO Robin Li said in a statement annoucing the results.

About 20% of Baidu’s traffic as of 2012 comes from mobile search, according to the company, and the Q3 earnings report showed that mobile search traffic was up 110% from Q3 last year and 25% from the previous quarter.

The company vowed to invest aggressively into mobile business which added to worries that it would lead to a rise of expenses on research and development. 

Besides, huge investments might as well wear down the company’s profit as Baidu announced this September to invest $1.6billion into a cloud computing center, pursuing an one-stop service integrating search, information, map, as well as other services.