Candlesticks are formed by the open, high, low and closing price of a security in a specified unit of period (e.g. on a daily, weekly or monthly basis). Candlestick charts cannot be drawn if no opening prices are available. If the closing price is below the opening price, then a filled candlestick is drawn (displayed as blue in our Java Charting System). On the contrary, if the closing price is above the opening price, then a hollow candlestick is drawn (displayed as white in our Java Charting System). The hollow or filled portion of the candlestick is called the body (or "real body"). The long thin lines above and below the body represent the high/low range of the period, which are usually called shadows (or wicks and tails).