Pair Spread Indicator

The indicator shows the difference in price between the two instruments.:

• Graph in the form of a histogram of the difference in price between the two instruments in a separate window. Ideal for related tools for example:  BRN -- WTI,  GOLD -- 50* Silver, DJ -- 14*S&P500, etc;
• Calculation method: closing price (open, high, low) N-bars back;
• Moving average on the histogram;
• Averaging options for the moving average: simple, exponential, smoothed, etc;
• The negative coefficient of one of the tools will change the chart by the sum of prices: tool_1 + tool_2;
• Indication of specified levels on the spread chart.