This ProBuilder script calculates the percentage change between the closing price of the previous trading day and the opening price of the current trading day. It also displays this information on the chart for visual analysis.

DEFPARAM CalculateOnLastBars = 2000
DEFPARAM DrawOnLastBarOnly = true
Offset1 = 15 * pipsize
Offset2 = Offset1 * 2

IF time = 163500 THEN
    ClosingPrice = close
ENDIF

IF time = 080000 THEN
    Percentage = 100 - ((close * 100) / ClosingPrice)
    MyBar = BarIndex
    MyPrice = high
ENDIF

DRAWTEXT("Price 16:35 #ClosingPrice#", MyBar, MyPrice + offset1) COLOURED(0,128,0,255)
DRAWTEXT("Difference #Percentage#", MyBar, MyPrice + offset2) COLOURED(128,0,0,255)

RETURN

This script is structured to perform specific actions based on the time of the trading day, using conditional statements to capture and calculate data at precise moments. Here’s a breakdown of its functionality:

• Initialization of Parameters: The script starts by setting up parameters to limit calculations to the last 2000 bars and to draw annotations only on the last bar.
• Capturing the Previous Day’s Close: It checks if the current time is 16:35 (assumed to be the market close time). If true, it stores the closing price at that time.
• Calculating Opening Percentage Change: At 08:00 the next day (assumed opening time), the script calculates the percentage change from the previous day’s close to the current price at open.
• Displaying Results: It uses the DRAWTEXT function to display the closing price and the percentage difference on the chart. The text is positioned relative to the high price of the current bar at specific offsets, and colored for distinction.

This example is useful for traders who need to quickly assess overnight price changes and visualize them directly on the trading chart.