This ProBuilder code snippet demonstrates how to calculate the Maximum Adverse Excursion (MAE) and Maximum Favorable Excursion (MFE) for trading strategies. MAE measures the largest loss observed in a trade before it is closed, while MFE assesses the largest profit.

// Define the entry price
entryPrice = close

// Calculate MAE and MFE
MAE = max(entryPrice - low, 0)
MFE = max(high - entryPrice, 0)

// Plot MAE and MFE on the chart
GRAPH MAE as "MAE" coloured("red")
GRAPH MFE as "MFE" coloured("green")

Explanation of the Code:

• Define the Entry Price: The variable entryPrice is set to the closing price of the stock at the time of the trade entry.
• Calculate MAE: MAE is calculated as the maximum difference between the entry price and the lowest price (low) after the entry, but only if this difference is positive. This represents the worst potential loss after entering the trade.
• Calculate MFE: MFE is calculated as the maximum difference between the highest price (high) after the entry and the entry price, again only if this difference is positive. This represents the best potential profit after entering the trade.
• Plotting MAE and MFE: Both MAE and MFE are plotted on the chart with distinct colors and line widths for clear visualization. MAE is plotted in red and MFE in green, each with a line width of 2.

This snippet is useful for traders and analysts to visually assess the risk and potential of trades over their duration directly on the chart.