Several other companies in that market went down a similar amount, so it doesn't seem to be extraordinary. I would expect a lot of tech investors to move their money to McAffe after that announcement hoping to get something out of it.
What matters is what happens after now. If it continues to go down for a long time, it might be a problem.
http://www.google.com/finance?client=ob&q=NASDAQ:INTC
Several other companies in that market went down a similar amount, so it doesn't seem to be extraordinary. I would expect a lot of tech investors to move their money to McAffe after that announcement hoping to get something out of it.
What matters is what happens after now. If it continues to go down for a long time, it might be a problem.