NEW YORK ( TheStreet) -- Prana Biotechnology ( PRAN) was skyrocketing for the second straight day Tuesday after it published data in the science journal PLoS One on the ability of its drug PBT2 to restore cognition in mice stricken by Alzheimer's disease. The stock was soaring 43% to $3.90. Volumes jumped to nearly 22 million in noon trading. Volumes have typically been under 300,000 in the last three months.

Adeona Pharmaceuticals ( AEN) was another pharmaceutical company gaining on unusual volumes, climbing 18.8% to $1.75. There were no company announcements driving the move, although Adeona is developing a clinical-stage oral, gastro-retentive and sustained-release medical food candidate for the dietary management of Alzheimer's.

Rare earth stocks were gaining after China rare earth exports data showed prices were more than double last year's average. China's exports of rare earth metals burst through the $100,000-per-ton mark for the first time in February, up almost nine-fold from a year before, while the volume of trade stayed far below historical averages, according to a Reuters report. The stock of Rare Element Resources ( REE) was jumping 13% to $11.72.

Shares of China GengSheng Minerals ( CHGS) and China Shen Zhou ( SHZ) gained 32% and 19% respectively. Avalon Rare Metals ( AVL) and Qiao Xing Universal Resources ( XING) also gained.

Chinese internet stock Dangdang ( DANG) was gaining 8.7% to $20.56 after Piper Jaffray upgraded the stock to overweight from neutral but lowered its price target to $25 from $30 previously.

Shares of online gaming software company Cryptologic ( CRYP) were surging 17% to $1.28 after its fourth-quarter loss narrowed to 6 cents a share from $1.98.

--Written by Shanthi Bharatwaj in New York

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