This has the been the most famous and age old question regarding Stock Trading. Simply due to the fact that 'When to Buy and When to Sell' is the core function behind stock trading and if you're an expert at deciding this, you can easily be a Pro at trading and end up unbelievably rich!!
Sorry to disappoint you though, but there's really no hard and core rule regarding when to buy and sell. That's the harsh and cold truth. Some may call it intuition, luck or sometimes pretty decent hard work and thought and decision making skills. However it is said and done, there are really a few basic things that you should know that could actually save your life in the stock market and hopefully not end up making losses for you.
When to buy?
Actually most people think or it may seem very appealing to buy a stock which has it's price moving up. It may logically seem valid. The price is moving up so it will continue further more and when I have enough profit I'll sell it. Just like that. But that's not the correct way to approach the market. You should always focus on stocks that have decreasing price movements. or more like stocks that have lost it's market price and fallen down to a low value. Why? Simply because, if a share was performing well and had dropped to a lower level, it has a HUGE potential to reach back to it's previous price or even further more. A price that is already increasing only has a huge potential to drop. So always we should eye for stocks that have recently lost it's value. Buy them quickly and wait till the prices recover. You cannot loose this way, because the price was already down it wouldn't go any further down but only up. So guaranteed you will end up with a profit.
When to sell?
Buy and sell may seem like two opposites, and it is, but the same core rules as of buying shares apply for selling shares. This doesn't mean that you have to sell when the prices have dropped. The ideal time to sell a stock would be when it shows signs of dropping price. Now, if you picked a stock at a lower value as I've mentioned above any increase in price would earn you a profit, so when the stock shows even the slightest signs of dropping prices, sell them. Don't wait thinking it'll recover, just sell it. You won't loose anything since you bought at a lower price.
So that's about it.
This is NOT buying/selling recommendation.