Small-cap stocks spent most of their time in negative territory Monday as they scraped under the broad indices, but the sector caught up to burst into the green late in the trading day.

One of the biggest winners was GigaBeam ( GGBM), which soared some 21% on Friday's postclose announcement that a "key reseller" for the Saudi Arabian government had ordered two of its WiFiber links. Financial terms weren't disclosed. Shares of the Durham, N.C., firm were up 91 cents to $5.26.

Coast Bank of Florida ( CFHI) catapulted 27.2% after First Banks agreed to buy it for around $3.40 a share in cash, a price that represents a 49.1% premium to the stock's Friday closing price. The $22.1 million deal will likely close in the fourth quarter. Shares were changing hands at $2.90.

Almost Family ( AFAM), meanwhile, jumped 10.1% to $17.82 on positive second-quarter results. The Louisville, Ky., home-nursing-services company more than doubled its continuing-operations income from last year to $2 million, or 35 cents a share, on revenue that surged 51.8% to $32.7 million.

On the downswing today, however, was drugmaker Santarus ( SNTS). The San Diego-based company sharply narrowed its loss to 25 cents a share -- 6 cents better than Thomson Financial's targets -- but also rescinded its 2008 revenue guidance, which had predicted revenue of more than $200 million. The company also expects a net loss for that year, and pegged 2007 revenue at a below-par range of $90 million to $95 million. Shares surrendered $1.36, or 26.4%, to $3.80.

Standard Motor Products ( SMP - Get Report), which makes replacement parts for motor vehicles, plunged 24.4% on essentially flat continuing-operations earnings of 30 cents a share vs. last year, coming in 2 cents below two analysts' targets. Revenue, at $217 million, represents a 5.3% year-over-year decline and misses the sole analyst's estimate by $13.5 million. Shares of the Long Island City, N.Y., company were down $2.79 to $8.63.

Radio One ( ROIAK), finally, sank 18.5% to $3.96 after the Washington-based media company announced that its long-standing chief financial officer, Scott Royster, will step down at the end of the year.

The Russell 2000, of which Santarus, Standard Motor, and Radio One are all components, was nonetheless climbing 1.4% at 765.79 as the S&P SmallCap 600 rose 1.2% to 405.42.