Smurfit-Stone Container Corp. (NYSE: SSCC) shares climbed 27.3 percent to $35.03, on volume of 36,237,477 shares, or more than 40 times its normal daily avearge after Rock-Tenn Co. said it would buy the container-board producer for $3.5 billion

Microsoft Inc. (Nasdaq: MSFT) dealt in 19,891,427 shares Monday, gaining on its full-day average of 57,649,200. Share prices moved higher 1.4 percent to $28.40 after three more executives left the company.

Onstream Media Corporation (Nasdaq: ONCM) saw its shares tumble 12.1 percent to $1.23 near midday Monday. Volume for the stock was 140,996 shares, still better by 50 percent its daily average. ONSM is an online service provider of live and on-demand Internet video, corporate audio and web communications and content management applications.