Profitable Mondays & Losing Fridays

Here's a Pine Script that marks profitable Mondays and losing Fridays for a given stock:

Explanation

Input Parameter: The script allows you to input the stock symbol, defaulting to SPX.
Daily Returns: It calculates the daily return based on the closing price.
Day Identification: It checks if the current day is Monday or Friday.
Conditions:
Profitable Mondays: Marks with a green background if Monday's return is positive.
Losing Fridays: Marks with a red background if Friday's return is negative.
Visualization: Uses bgcolor to highlight the respective days on the chart.

You can adjust the stockSymbol input to analyze different stocks.