As long as a company is growing I guess that its valuation is constantly moving in the right direction. If you feel that fundamentals still justify the price, there's no reason to sell.
Philip Fisher went even further with this reasoning. He would keep his position on a stock, even though he felt that valuation was too rich given the current fundamentals. Of course, he had to be very confident in the management and the future of the company. His analysis was so profound that most of the time he felt very comfortable to follow this strategy.
Yep. There was a 6% range today -- quite large. I'm glad it finished up. I've re-valuated the stock and I've put my sell at 12.13. A few more jumps like today and we'll be there by the next earnings report.