American Medical Systems Holdings Inc. (Nasdaq: AMMD) shares gained 32.1% to $29.50 on volumes topping 17 million shares, in contrast to a daily average of less than one million. This, after Endo Pharmaceuticals Holdings Inc. (Nasdaq: ENDP) said it would buy the urological medical-devices supplier for about $2.6 billion.

Level 3 Communications Inc. (Nasdaq: LVLT) shares tumbled off the shelves early Monday, trading in 120 million in all, or six times the business it would normally do in a day. Prices for the stock forged ahead 14.9% to $1.66, on word the company was set to buy Global Crossing for $2 billion.

QuickLogic Corp. (Nasdaq: QUIK) shares fell 16.8% to $4.05, on volume of 753,000 or nearly double its full-day average, after the semiconductor company late Friday lowered its first-quarter revenue outlook.