Z Score Trend Following Strategy

/*backtest
start: 2023-04-23 00:00:00
end: 2024-04-28 00:00:00
period: 1d
basePeriod: 1h
exchanges: [{"eid":"Futures_Binance","currency":"BTC_USDT"}]
*/

// This Pine Script™ code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © PresentTrading

// This strategy employs a statistical approach by using a Z-score, which measures the deviation of the price from its moving average normalized by the standard deviation.
// Very simple and effective approach

//@version=5
strategy('Price Based Z-Trend - strategy [presentTrading]',shorttitle = 'Price Based Z-Trend - strategy [presentTrading]', overlay=false, precision=3, 
         commission_value=0.1, commission_type=strategy.commission.percent, slippage=1, 
         currency=currency.USD, default_qty_type=strategy.percent_of_equity, default_qty_value=10, initial_capital=10000)

// User-definable parameters for the Z-score calculation and bar coloring
tradeDirection = input.string("Both", "Trading Direction", options=["Long", "Short", "Both"]) // User selects trading direction

priceDeviationLength = input.int(100, "Standard Deviation Length", step=1) // Length for standard deviation calculation
priceAverageLength = input.int(100, "Average Length", step=1) // Length for moving average calculation
Threshold = input.float(1, "Threshold", step=0.1) // Number of standard deviations for Z-score threshold
priceBar = input(title='Bar Color', defval=true) // Toggle for coloring price bars based on Z-score


// Z-score calculation based on user input for the price source (typically the closing price)
priceSource = input(close, title="Source")
priceZScore = (priceSource - ta.ema(priceSource, priceAverageLength)) / ta.stdev(priceSource, priceDeviationLength) // Z-score calculation

// Conditions for entering and exiting trades based on Z-score crossovers
priceLongCondition = ta.crossover(priceZScore, Threshold) // Condition to enter long positions
priceExitLongCondition = ta.crossunder(priceZScore, -Threshold) // Condition to exit long positions

longEntryCondition = ta.crossover(priceZScore, Threshold)
longExitCondition = ta.crossunder(priceZScore, -Threshold)
shortEntryCondition = ta.crossunder(priceZScore, -Threshold)
shortExitCondition = ta.crossover(priceZScore, Threshold)


// Strategy conditions and execution based on Z-score crossovers and trading direction
if (tradeDirection == "Long" or tradeDirection == "Both") and longEntryCondition
    strategy.entry("Long", strategy.long) // Enter a long position

if (tradeDirection == "Long" or tradeDirection == "Both") and longExitCondition
    strategy.close("Long") // Close the long position

if (tradeDirection == "Short" or tradeDirection == "Both") and shortEntryCondition
    strategy.entry("Short", strategy.short) // Enter a short position

if (tradeDirection == "Short" or tradeDirection == "Both") and shortExitCondition
    strategy.close("Short") // Close the short position


// Dynamic Thresholds Visualization using 'plot'
plot(Threshold, "Dynamic Entry Threshold", color=color.new(color.green, 50))
plot(-Threshold, "Dynamic Short Entry Threshold", color=color.new(color.red, 50))


// Color-coding Z-Score
priceZScoreColor = priceZScore > Threshold ? color.green : 
              priceZScore < -Threshold ? color.red : color.blue
plot(priceZScore, "Z-Score", color=priceZScoreColor)

// Lines
hline(0, color=color.rgb(255, 255, 255, 50), linestyle=hline.style_dotted)

// Bar Color
priceBarColor = priceZScore > Threshold ? color.green :
           priceZScore > 0 ? color.lime :
           priceZScore < Threshold ? color.maroon :
           priceZScore < 0 ? color.red : color.black
barcolor(priceBar ? priceBarColor : na)