How many stocks have you traded last year and wished you had held on a little longer? Buy and Hold is dead only when it's about multi-year time frames or retirement funds. I strongly believe everyone should re-evaluate all their holdings and also the effect the general markets might have on them regularly. The market has taught this lesson multiple times over the last decade.
However, you should always do what works for you. You are buying a stock for a reason and that reason can very well be 'value' or 'long-term growth'. If the general market plays along it is almost always a mistake to sell such a stock and lock in profits when your original buy reason is still valid. You make money but you miss out on the big returns. On the other side, I believe that if you buy a stock for news, earnings or any type of short-term expectations then you shouldn't make yourself come up with a new long-term reason when the stock doesn't behave the way you expected it to. Most of my losses in previous years came from me not sticking to my original plan so now there is no 'hope' involved anymore and I have no problems selling a stock for a loss if it doesn't do what I wanted it to. I can feel comfortable with all my holdings that way and this works out very well.
News 
Market Data 
Discover 
