This ProBuilder script demonstrates how to manage buying and selling financial instruments within the same bar (or candlestick) without accumulating multiple orders. The script ensures that only one order is active at any time by using a counter to track whether the market is entered or exited.

DEFPARAM CumulateOrders = true
defparam preloadbars=0

IF OnMarket and count=1 THEN
    SELL AT MARKET
    EXITSHORT AT MARKET
    count=0
ENDIF

if low[0] <= low[1] and count=0 then
    buy 1 shares at market
    count=1
endif

Explanation of the Code:

• DEFPARAM CumulateOrders = true: This line sets the parameter to allow multiple orders within the same bar. However, the script logic prevents this from happening.
• defparam preloadbars=0: This parameter sets the number of bars to preload, which is set to 0 as the script does not require historical data beyond the current and previous bars.
• IF OnMarket and count=1 THEN: This condition checks if there is currently an open position and if the count is 1, indicating an open position that needs to be closed.
• SELL AT MARKET and EXITSHORT AT MARKET: These commands close the existing long or short position at the current market price.
• count=0: Resets the count to 0, indicating that there are no open positions.
• if low[0] <= low[1] and count=0 then: This condition checks if the current bar's low is less than or equal to the previous bar's low and ensures no positions are currently open (count=0).
• buy 1 shares at market: Executes a buy order for 1 share at the current market price.
• count=1: Sets the count to 1, indicating an open position.

This script is useful for traders who need to manage their positions strictly within the same bar, avoiding multiple simultaneous positions while still reacting quickly to market conditions.