RE:Investment strategySell 1/2 on a double is s nice easy rule. It may cost you a lot of money in the long run though. I treat stocks more like kids, you don't treat them all the same-- depends on the maturity, potential, the environment.
A $50 stock is very different then a 95 cent stock. If I think it has the potential for 4x, 5x+ growth, I will sell some as it gets close to a double to bring down my investment at risk, but don't want to lose out on exponential returns on too large a a position. Selling some (20-25%) is also downside protection in case the market or just that stock goes for a temporary correction. this is especially true for stocks in this price range.