http://finance.yahoo.com/news/mindspeed-announces-definitive-agreement-acquired-212200728.html
MSPD is being acquired at $5.05 per share. It closed yesterday at $3.04. that represents a 66% premium. The typical premium is 25-40%. so this represents a huge premium over market price.
Frequently these merger deals run in bunches. It is not uncommon to see the stock price of other companies in the industry go up in sympathy. Right now VTSS is sitting as flat as ever -- no change in price from yesterday.