NEW YORK ( TheStreet) -- Small-cap stocks were under pressure Tuesday with the Russell 2000 Index down 0.1% in afternoon trading, but a handful of stocks were bucking the trend.

Shares of Unisys ( UIS) were seeing the biggest gains in the small-cap sector, rising 15.5% to $33.89 after its fourth-quarter earnings came in ahead of estimates. The tech company said it earned $95.2 million, or $2.29 per share, trouncing analyst estimates of 90 cents per share.

Shares of biopharma company MannKind ( MNKD) were up 9.5% to $5.19 without any major news behind the move. CEO Alfred Mann has been buying the stock over the past several months and also bought more shares after U.S. regulators rejected its drug, Afrezza, that treats hypoglycemia, causing the stock to plummet.

The company is facing multiple lawsuits from investors alleging that it hyped the importance of the drug for its business but failed to disclose how risky the product was, among other things.

Solar companies were rallying on Tuesday after MEMC Electronics ( WFR) reported stronger-than-expected results on Tuesday and issued positive guidance for 2011. Shares of Renesola ( SOL), SunPower ( SPWRA), JA Solar ( JASO), Trina Solar ( TSL) and Solarfun Power ( SOLF) were seeing gains between 5% and 7%.

Shares of Savvis ( SVVS) soared 5% to $33.05 as it continues to attract interest as the next takeover target in the cloud computing sector.

Rare earth play Rare Element Resources ( REE) was climbing 6.5% to $13.49.

Shares of Helix Energy ( HLX), Cirrus Logic ( CRUS) and Take-Two Interactive ( TTWO) were among the other notable winners in the small-cap sector on Tuesday trading.

-- Written by Shanthi Bharatwaj in New York

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