NEW YORK ( TheStreet) -- Baidu ( BIDU) was a big winner before market open on Tuesday, boosted by its plan to acquire smartphone apps developer 91 Wireless. The Chinese search giant announced on Tuesday that it signed a memorandum of understanding to buy a 100% interest in NetDragon subsidiary 91 Wireless for $1.9 billion. Baidu shares rose 7.09% to $108.79 in premarket trading. The company was also one of the most active premarket Nasdaq stocks on share volume of 335,725. Facebook ( FB) was a more modest gainer, rising 0.46% to $26.40. The social networking company was another active premarket stock on share volume of 346,499. ZNGA ( ZNGA), a key Facebook partner, was also heading northward, rising 1.97% to $3.62. Tesla ( TSLA) shares, however, were off 1.46% at $125.40 in premarket trading. Emulex ( ELX) was another laggard, falling 1.92% to $8.16 as investors digested the company's CEO transition and its preliminary fiscal fourth-quarter results. Vodafone ( VOD) shares dipped 0.27% to $29.37. --Written by James Rogers in New York. Follow @jamesjrogers >To submit a news tip, send an email to: email@example.com.