It's been a good year for China's leading search engine. Shares of Baidu (BIDU -1.84%) are up a whopping 73% with a handful of trading days to go, easily beating the market.

It didn't start out that way. Baidu stock was trading as much as 17% lower in 2013 when it bottomed out in April. The market was concerned that Baidu wasn't doing enough to matter in mobile. There were also concerns that Qihoo 360 (QIHU.DL) was gaining market share in search after launching its own platform last year. 

Baidu bounced back. Some timely acquisitions assured investors that Baidu wouldn't have all of its eggs in desktop search. The dot-com speedster's heady growth and rosy outlooks also silenced the fears that it was losing ground in the world's most populous nation.

Deals and growth
The first deal to turn heads came in early May, just weeks after Baidu stock hit a fresh 52-week low. Baidu acquired PPS.tv's streaming video service in a $370 million deal. Combining PPS.tv with its own iQiyi transformed Baidu into an online video juggernaut that would rival market leader Youku (NYSE: YOKU) for market dominance. Video is naturally not as lucrative as paid search, but investors have gotten excited about streaming video's prospects in China. Youku hit a 52-week high this month despite posting larger than expected losses in two of the past three quarters.

Baidu shares began to move higher after the PPS.tv purchase, but the real game changer came two months later when it shelled out $1.9 billion to snap up China's leading mobile apps marketplace operator. It may have been a stiff price to pay, but Baidu's good for the money. Even after a year of major acquisitions, the Chinese bellwether had more than $7 billion in cash and short-term investments on its balance sheet by the end of September. 

Making big bets on streaming video and mobile apps will pay off in the future, but a big reason for Baidu more than doubling off of April's low is that it's doing a nice job of growing. Baidu's third quarter was a gem with revenue soaring 42% for the period. More importantly, its outlook for the final quarter is even more promising. Baidu sees revenue growth accelerating to the point where it posts 46% to 50% top-line growth during the current quarter.

Baidu may have started out the year as a lamb, but it's closing it out as a lion.