Small-cap stocks were on the rise along with the broader market Monday. The Russell 2000 added 1.7% to 732.41, and the S&P SmallCap 600 climbed 1.5% to 385.06.

Among the winners, Phoenix, Ariz.-based Radyne ( RADN) saw shares soar 44% to $11.11 on news that Comtech ( CMTL) will buy the maker of communication network systems for $11.50 a share in cash. Comtech was gaining 3.8% to $42.85.

Stifel Financial ( SF) shares shot up 14% to $53.60. The St. Louis-based investment brokerage posted first-quarter non-GAAP income of $18.3 million, or $1.03 a share, vs. $13.2 million, or 86 cents a share, a year ago. Analysts polled by Thomson Reuters were looking for 89 cents a share.

On the losing side, Gencor ( GENC), an Orlando, Fla., maker of heavy machinery for highway construction, fell 36% to $20.68. The company reported fiscal second-quarter earnings of $1.3 million, or 15 cents a share, down from $10.5 million, or $1.08 a share, in the year-ago quarter.

Also falling, Cumulus Media ( CMLS) -- which buys, operates and develops radio stations -- fell to a new 52-week low. The Atlanta-based firm announced that a merger deal with Cumulus CEO Lew Dickey and an affiliate of Merrill Lynch Global Private Equity has fallen through. The investor group will pay a termination fee of $15 million, and Cumulus announced it may implement a stock repurchase plan. The stock sank 23% to $4.45.

Liquid natural gas company Cheniere Energy ( LNG) also plummeted to a new 52-week low. Citigroup downgraded the Houston firm to hold from buy, and RBC Capital Markets downgraded it to underperform from outperform. On Friday, Cheniere had posted a first-quarter loss of $49.9 million, or $1.06 a share, vs. a loss of $34.6 million, or 63 cents a share, a year ago. The Street was looking for a loss of $1.08 a share. Shares were falling 21% to $4.20 Monday.

Finally, Irvine, Calif., homebuilder Standard Pacific ( SPF) tumbled 12% to $3.34. The company widened it first-quarter loss to $216.4 million, or $3.34 a share, from $40.8 million, or 63 cents a share, a year ago. The loss included after-tax impairment charges of $117.9 million, or $1.82 a share. Revenue fell year over year to $348.2 million from $651.1 million.