diff --git a/Include/MyIncludes/Polynomial_Regression_Slope_Calculator.mqh b/Include/MyIncludes/Polynomial_Regression_Slope_Calculator.mqh
new file mode 100644
index 0000000..326fc50
--- /dev/null
+++ b/Include/MyIncludes/Polynomial_Regression_Slope_Calculator.mqh
@@ -0,0 +1,189 @@
+//+------------------------------------------------------------------+
+//|                   Polynomial_Regression_Slope_Calculator.mqh     |
+//|      Engine for the Polynomial Regression Slope oscillator.      |
+//|                                        Copyright 2025, xxxxxxxx  |
+//+------------------------------------------------------------------+
+#property copyright "Copyright 2025, xxxxxxxx"
+
+#include <MyIncludes\HeikinAshi_Tools.mqh>
+
+//+==================================================================+
+class CPolynomialRegressionSlopeCalculator
+  {
+protected:
+   int               m_period;
+   double            m_price[];
+
+   virtual bool      PreparePriceSeries(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[]);
+
+public:
+                     CPolynomialRegressionSlopeCalculator(void) {};
+   virtual          ~CPolynomialRegressionSlopeCalculator(void) {};
+
+   bool              Init(int period);
+   void              Calculate(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[],
+                               double &slope_buffer[]);
+  };
+
+//+------------------------------------------------------------------+
+//|                                                                  |
+//+------------------------------------------------------------------+
+class CPolynomialRegressionSlopeCalculator_HA : public CPolynomialRegressionSlopeCalculator
+  {
+private:
+   CHeikinAshi_Calculator m_ha_calculator;
+protected:
+   virtual bool      PreparePriceSeries(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[]) override;
+  }; // Full definition below
+
+//+==================================================================+
+//|                 METHOD IMPLEMENTATIONS                           |
+//+==================================================================+
+
+//+------------------------------------------------------------------+
+//|                                                                  |
+//+------------------------------------------------------------------+
+bool CPolynomialRegressionSlopeCalculator::Init(int period)
+  {
+   m_period = (period < 3) ? 3 : period;
+   return true;
+  }
+
+//+------------------------------------------------------------------+
+//|                                                                  |
+//+------------------------------------------------------------------+
+void CPolynomialRegressionSlopeCalculator::Calculate(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[],
+      double &slope_buffer[])
+  {
+   if(rates_total < m_period)
+      return;
+   if(!PreparePriceSeries(rates_total, price_type, open, high, low, close))
+      return;
+
+   int start_pos = m_period - 1;
+
+   for(int i = start_pos; i < rates_total; i++)
+     {
+      double sum_x=0, sum_y=0, sum_x2=0, sum_xy=0, sum_x3=0, sum_x4=0, sum_x2y=0;
+      for(int j = 0; j < m_period; j++)
+        {
+         double x = j;
+         double y = m_price[i - m_period + 1 + j];
+         sum_x += x;
+         sum_y += y;
+         sum_x2 += x*x;
+         sum_xy += x*y;
+         sum_x3 += x*x*x;
+         sum_x4 += x*x*x*x;
+         sum_x2y += x*x*y;
+        }
+
+      double b=0, c=0;
+      double n = m_period;
+
+      double D = n * (sum_x2 * sum_x4 - sum_x3 * sum_x3) - sum_x * (sum_x * sum_x4 - sum_x2 * sum_x3) + sum_x2 * (sum_x * sum_x3 - sum_x2 * sum_x2);
+      if(MathAbs(D) < 1e-10)
+         continue;
+
+      double Db = n * (sum_xy * sum_x4 - sum_x2y * sum_x3) - sum_x * (sum_y * sum_x4 - sum_x2 * sum_x2y) + sum_x2 * (sum_y * sum_x3 - sum_x2 * sum_xy);
+      double Dc = n * (sum_x2 * sum_x2y - sum_x3 * sum_xy) - sum_x * (sum_x * sum_x2y - sum_x2 * sum_xy) + sum_y * (sum_x * sum_x3 - sum_x2 * sum_x2);
+
+      b = Db / D;
+      c = Dc / D;
+
+      //--- Calculate the slope at the current bar (x = n - 1)
+      double x_current = n - 1;
+      slope_buffer[i] = b + 2 * c * x_current;
+     }
+  }
+
+
+//+------------------------------------------------------------------+
+//|                                                                  |
+//+------------------------------------------------------------------+
+bool CPolynomialRegressionSlopeCalculator::PreparePriceSeries(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[])
+  {
+   if(ArraySize(m_price) != rates_total)
+      if(ArrayResize(m_price, rates_total) != rates_total)
+         return false;
+
+   switch(price_type)
+     {
+      case PRICE_CLOSE:
+         ArrayCopy(m_price, close, 0, 0, rates_total);
+         break;
+      case PRICE_OPEN:
+         ArrayCopy(m_price, open, 0, 0, rates_total);
+         break;
+      case PRICE_HIGH:
+         ArrayCopy(m_price, high, 0, 0, rates_total);
+         break;
+      case PRICE_LOW:
+         ArrayCopy(m_price, low, 0, 0, rates_total);
+         break;
+      case PRICE_MEDIAN:
+         for(int i=0; i<rates_total; i++)
+            m_price[i] = (high[i]+low[i])/2.0;
+         break;
+      case PRICE_TYPICAL:
+         for(int i=0; i<rates_total; i++)
+            m_price[i] = (high[i]+low[i]+close[i])/3.0;
+         break;
+      case PRICE_WEIGHTED:
+         for(int i=0; i<rates_total; i++)
+            m_price[i] = (high[i]+low[i]+close[i]+close[i])/4.0;
+         break;
+      default:
+         return false;
+     }
+   return true;
+  }
+
+//+------------------------------------------------------------------+
+//|                                                                  |
+//+------------------------------------------------------------------+
+bool CPolynomialRegressionSlopeCalculator_HA::PreparePriceSeries(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[])
+  {
+   double ha_open[], ha_high[], ha_low[], ha_close[];
+   ArrayResize(ha_open, rates_total);
+   ArrayResize(ha_high, rates_total);
+   ArrayResize(ha_low, rates_total);
+   ArrayResize(ha_close, rates_total);
+   m_ha_calculator.Calculate(rates_total, open, high, low, close, ha_open, ha_high, ha_low, ha_close);
+
+   if(ArraySize(m_price) != rates_total)
+      if(ArrayResize(m_price, rates_total) != rates_total)
+         return false;
+
+   switch(price_type)
+     {
+      case PRICE_CLOSE:
+         ArrayCopy(m_price, ha_close, 0, 0, rates_total);
+         break;
+      case PRICE_OPEN:
+         ArrayCopy(m_price, ha_open, 0, 0, rates_total);
+         break;
+      case PRICE_HIGH:
+         ArrayCopy(m_price, ha_high, 0, 0, rates_total);
+         break;
+      case PRICE_LOW:
+         ArrayCopy(m_price, ha_low, 0, 0, rates_total);
+         break;
+      case PRICE_MEDIAN:
+         for(int i=0; i<rates_total; i++)
+            m_price[i] = (ha_high[i]+ha_low[i])/2.0;
+         break;
+      case PRICE_TYPICAL:
+         for(int i=0; i<rates_total; i++)
+            m_price[i] = (ha_high[i]+ha_low[i]+ha_close[i])/3.0;
+         break;
+      case PRICE_WEIGHTED:
+         for(int i=0; i<rates_total; i++)
+            m_price[i] = (ha_high[i]+ha_low[i]+ha_close[i]+ha_close[i])/4.0;
+         break;
+      default:
+         return false;
+     }
+   return true;
+  }
+//+------------------------------------------------------------------+