Aeroflex surged 19% on news of a $1 billion buyout by General Atlantic and Francisco Partners. Shareholders of the Plainview, N.Y., microelectrics firm will get $13.50 a share in cash, a 22.6% premium to Friday's closing price. Shares rose $2.13 to $13.14.

Pathmark rose 10% after the New Jersey-based supermarket chain set plans to sell itself to A&P for about $1.3 billion in cash and stock. The deal should close between September 2007 and February 2008. Pathmark was jumping $1.12 to $12.37, while A&P was adding 92 cents, or 3%, to $31.78.

Gastar Exploration ( GST) rose 14% after saying work was finished on an East Texas gas well in which it has a 50% postcompletion working interest. The initial gross daily flow rate is about 12 million cubic feet, says the Houston-based company. Shares were rising 21 cents to $1.71.

Myriad Genetics ( MYGN - Get Report) gained 7% after Flurizan, its treatment for mild Alzheimer's disease, yielded what it called highly statistically significant results in a two-year midphase study. Shares of Salt Lake City-based Myriad were up $2.23 to $33.46.

Memory Pharma lost nearly a third of its value after its Mem 1003 drug failed to reduce acute mania in individuals with bipolar disorder. Shares of the Montvale, N.J., company were off 97 cents to $2.16.

Home Solutions of America sank 19% after trimming a dime from its full-year earnings guidance. The company now expects to make 43 cents to 46 cents a share, due to sector weakness and government delays in New Orleans projects. Fourth-quarter income should be between 5 cents and 7 cents a share. The analyst who follows the Dallas-based company expects earnings of 16 cents a share for the quarter and 49 cents for the year. Shares were falling $1.09 to $4.78.

OM Group ( OMG) dropped 8% after swinging to a fourth-quarter loss. Continuing-operations losses came to 58 cents a share in the fourth quarter, compared with break-even last year. Analysts had sought 72-cent profits from the metals-processor. Cleveland-based OMG surrendered $3.80 to $43.66.

Lawson Products ( LAWS - Get Report) dropped 4% after reporting a sharp drop in fourth-quarter earnings. The Des Plaines, Ill., company made $1.3 million, or 16 cents a share, down from last year's $9.6 million, or $1.06 a share. Shares were retreating $1.39 to $34.70.