Small-cap stocks were virtually synchronous with the worst-performing major index Monday -- the

Nasdaq

-- but acquisitions helped keep the sector mostly in positive territory.

Opsware

( OPSW) catapulted 36.2% in furious trading after

Hewlett-Packard

(HPQ) - Get Report

agreed to buy it

for $14.25 a share, or $1.6 billion, in an all-cash transaction that will likely complete before the end of H-P's fiscal fourth quarter. California-based Opsware, a data-center automation-software firm, closed up $3.72 to $14. H-P shares slipped 11 cents to $48.43.

Similarly, Atlanta's

Cumulus Media

(CMLS) - Get Report

soared more than 32% to $11.12 on word it

agreed to be taken out

by a group led by CEO Lew Dickey and Merrill Lynch Global Private Equity for around $1.3 billion in cash. That pans out at $11.75 a share, or a 40.4% premium to Friday's close. The deal should close early next year.

Cal-Maine Foods

(CALM) - Get Report

shares were also riding high after the Jackson, Miss., shell-eggs distributor swung to a fiscal fourth-quarter profit of $18.3 million, or 77 cents a share. Revenue jumped 31.3% to $169.9 million. Shares ended 12.3% higher at $22.68.

The Russell 2000, which counts among its components all of the above stocks (sans H-P), had a jumpy day in the green before finishing down 0.1% to 835.62. The S&P SmallCap 600 was virtually flat at 437.74.

Among individual names in the red,

Nucryst Pharmaceuticals

( NCST), of Wakefield, Mass., gave back some of Friday's astronomical gains after an analyst with SunTrust Robinson said the leap -- which was spurred by regulatory approval of its broad-spectrum antimicrobial-barrier topical cream -- was an overreaction. He lowered the stock's rating to neutral from buy. Shares plunged 29.8% to $4.10.

Finally,

Thomas Group

(TGIS)

slid 18.3% after the Irving, Texas, management-services company reported it had earned just $1.9 million, or 17 cents a share, on shrinking revenue of $14 million. Last year it made 23 cents a share on sales of $15.6 million. Shares ended at $10.53.