Previous Day Open, High, Low, Close

Often called OHLC, the Open, High, Low, and Close of the previous day can tell you important things about the stock. Below is a bar chart which can tell us the OHLC from the previous day. 

OHLC tells us many things. If the Open and Close are far apart, it demonstrates a strong momentum. If Open and Close are close to each other, it demonstrates a weak momentum. To clarify, momentum tells us the rate at which the price is changing. If the momentum is strong, then the price changed very rapidly. High and Low shows us volatility. Volatility shows how far the prices deviate from the average price. From these values we can determine whether a stock is likely to increase in value rapidly and how often the stock moves form mean price.