If you search online about the very common and mostly used trading strategy, then you will find the Simple Moving Average Crossover strategy with 50 and 200 days. 50 and 200 are two different time graphs SMA (Simple Moving Average). These two give two signals bullish and bearish. So, if 50 SMA crosses above 200 SMA, it is a bullish indicator that means buying signal. On the contrary if 50 days SMA crosses beneath the 200 days SMA, it is a bearish signal ie., Selling signal.
Still have a doubt in your mind then backtest this strategy with your selected share and you will be shocked by the performance of the strategy.