The small-cap sector largely managed to stay afloat Thursday amid surging names like Acme Packet ( APKT).

The Burlington, Mass., company racked up 22.6% gains on second-quarter non-GAAP income of $5.7 million, or 9 cents a share. That tops the average analysts' estimate by a penny, according to Thomson Financial. Shares were up $2.35 to $12.77.

San Diego's Cubic ( CUB), which makes defense electronics and transportation-fare-collection systems, bounced 19.4% to $32.70 on a decisive earnings beat. Fiscal third-quarter earnings rose sharply to $11.2 million, or 42 cents a share, from 22 cents a share a year ago. Analysts were looking for 33 cents a share.

Both Acme and Cubic helped to prop up the Russell 2000, which was lately climbing 1.7 points, or 0.2%, to 779.62. The S&P SmallCap 600 added 0.4% to 412.53.

Elsewhere, BluePhoenix Solutions ( BPHX) rode high after the Israel-based business-software company inked a letter of intent to buy Texas-based Amalgamated Software North America. The deal is worth $9.5 million in cash, in addition to an earn-out for ASNA shareholders contingent on achievement of certain profit targets. BluePhoenix shares jumped $1.76, or 15.6%, to $13.06.

Pozen ( POZN) shares took a 43% free fall, however, after the Food and Drug Administration said it and partner GlaxoSmithKline ( GSK) need to collect more safety data on their proposed migraine drug Trexima. North Carolina-based Pozen lost $7.50 to $9.95; Glaxo ticked up 0.7% to $51.97.

In earnings, Liquidity Services ( LQDT) plunged some 26% after coming in a penny under consensus for per-share earnings in the fiscal third quarter, as well as pegging adjusted next-quarter income at 9 cents a share. Analysts looking for 12 cents. Shares of the Washington, D.C.-based auction-Web-site operator were changing hands at $12.42.

And toymaker RC2 ( RCRC) lost 19.5% after chopping at least 45 cents off its full-year income guidance for a range between $2.05 to $2.15 a share -- at least 50 cents under Wall Street expectations. Results for the second quarter, moreover, missed substantially on both top and bottom lines. Shares slumped $6.99 to $28.90.

If you liked this article you might like

Lackluster Finish for U.S. Stocks

Lackluster Finish for U.S. Stocks

Stocks Continue to Waver at the Flat Line

Stocks Continue to Waver at the Flat Line

Oil Slides as Stocks Post a Mixed Showing

Oil Slides as Stocks Post a Mixed Showing

Stocks Flutter Near the Flat Line

Stocks Flutter Near the Flat Line

Wall Street Falls Amid Inflation Talk

Wall Street Falls Amid Inflation Talk