diff --git a/Include/MyIncludes/PVI_NVI_Calculator.mqh b/Include/MyIncludes/PVI_NVI_Calculator.mqh
new file mode 100644
index 0000000..bce7c8f
--- /dev/null
+++ b/Include/MyIncludes/PVI_NVI_Calculator.mqh
@@ -0,0 +1,200 @@
+//+------------------------------------------------------------------+
+//|                                             PVI_NVI_Calculator.mqh |
+//|      VERSION 1.20: Added signal lines & corrected calculation.   |
+//|                                        Copyright 2025, xxxxxxxx  |
+//+------------------------------------------------------------------+
+#property copyright "Copyright 2025, xxxxxxxx"
+
+#include <MyIncludes\MovingAverage_Engine.mqh>
+#include <MyIncludes\HeikinAshi_Tools.mqh>
+
+enum ENUM_CANDLE_SOURCE { CANDLE_STANDARD, CANDLE_HEIKIN_ASHI };
+
+//+==================================================================+
+class CPVINVICalculator
+  {
+protected:
+   ENUM_APPLIED_VOLUME m_volume_type;
+   int                 m_signal_period;
+   ENUM_MA_TYPE        m_signal_ma_type;
+   double              m_price[];
+
+   virtual bool      PrepareSourceData(int rates_total, const double &open[], const double &high[], const double &low[], const double &close[]);
+   void              CalculateMA(const double &source_array[], double &dest_array[], int period, ENUM_MA_TYPE method, int start_pos);
+
+public:
+                     CPVINVICalculator(void) {};
+   virtual          ~CPVINVICalculator(void) {};
+
+   bool              Init(ENUM_APPLIED_VOLUME vol_type, int signal_p, ENUM_MA_TYPE signal_ma);
+   void              Calculate(int rates_total, const double &open[], const double &high[], const double &low[], const double &close[], const long &volume[],
+                               double &pvi_buffer[], double &nvi_buffer[], double &pvi_signal[], double &nvi_signal[]);
+  };
+
+//+------------------------------------------------------------------+
+//|                                                                  |
+//+------------------------------------------------------------------+
+class CPVINVICalculator_HA : public CPVINVICalculator
+  {
+private:
+   CHeikinAshi_Calculator m_ha_calculator;
+protected:
+   virtual bool      PrepareSourceData(int rates_total, const double &open[], const double &high[], const double &low[], const double &close[]) override;
+  };
+
+//+==================================================================+
+//|                 METHOD IMPLEMENTATIONS                           |
+//+==================================================================+
+
+//+------------------------------------------------------------------+
+//|                                                                  |
+//+------------------------------------------------------------------+
+bool CPVINVICalculator::Init(ENUM_APPLIED_VOLUME vol_type, int signal_p, ENUM_MA_TYPE signal_ma)
+  {
+   m_volume_type = vol_type;
+   m_signal_period = (signal_p < 1) ? 1 : signal_p;
+   m_signal_ma_type = signal_ma;
+   return true;
+  }
+
+//+------------------------------------------------------------------+
+//|                                                                  |
+//+------------------------------------------------------------------+
+void CPVINVICalculator::Calculate(int rates_total, const double &open[], const double &high[], const double &low[], const double &close[], const long &volume[],
+                                  double &pvi_buffer[], double &nvi_buffer[], double &pvi_signal[], double &nvi_signal[])
+  {
+   if(rates_total < 2)
+      return;
+   if(!PrepareSourceData(rates_total, open, high, low, close))
+      return;
+
+   pvi_buffer[0] = 1000;
+   nvi_buffer[0] = 1000;
+
+   for(int i = 1; i < rates_total; i++)
+     {
+      double price_change = m_price[i] - m_price[i-1];
+
+      if(volume[i] > volume[i-1])
+        {
+         pvi_buffer[i] = pvi_buffer[i-1] + price_change;
+         nvi_buffer[i] = nvi_buffer[i-1];
+        }
+      else
+         if(volume[i] < volume[i-1])
+           {
+            nvi_buffer[i] = nvi_buffer[i-1] + price_change;
+            pvi_buffer[i] = pvi_buffer[i-1];
+           }
+         else
+           {
+            pvi_buffer[i] = pvi_buffer[i-1];
+            nvi_buffer[i] = nvi_buffer[i-1];
+           }
+     }
+
+   int signal_start = m_signal_period;
+   CalculateMA(pvi_buffer, pvi_signal, m_signal_period, m_signal_ma_type, signal_start);
+   CalculateMA(nvi_buffer, nvi_signal, m_signal_period, m_signal_ma_type, signal_start);
+  }
+
+//+------------------------------------------------------------------+
+//|                                                                  |
+//+------------------------------------------------------------------+
+void CPVINVICalculator::CalculateMA(const double &source_array[], double &dest_array[], int period, ENUM_MA_TYPE method, int start_pos)
+  {
+   for(int i = start_pos; i < ArraySize(source_array); i++)
+     {
+      switch(method)
+        {
+         case EMA:
+         case SMMA:
+            if(i == start_pos)
+              {
+               double sum=0;
+               int count=0;
+               for(int j=0; j<period; j++)
+                 {
+                  if(source_array[i-j] != EMPTY_VALUE)
+                    {
+                     sum+=source_array[i-j];
+                     count++;
+                    }
+                 }
+               if(count > 0)
+                  dest_array[i]=sum/count;
+              }
+            else
+              {
+               if(method==EMA)
+                 {
+                  double pr=2.0/(period+1.0);
+                  dest_array[i]=source_array[i]*pr+dest_array[i-1]*(1.0-pr);
+                 }
+               else
+                  dest_array[i]=(dest_array[i-1]*(period-1)+source_array[i])/period;
+              }
+            break;
+         case LWMA:
+           {
+            double sum=0, w_sum=0;
+            for(int j=0; j<period; j++)
+              {
+               if(source_array[i-j] == EMPTY_VALUE)
+                  continue;
+               int w=period-j;
+               sum+=source_array[i-j]*w;
+               w_sum+=w;
+              }
+            if(w_sum>0)
+               dest_array[i]=sum/w_sum;
+           }
+         break;
+         default: // SMA
+           {
+            double sum=0;
+            int count=0;
+            for(int j=0; j<period; j++)
+              {
+               if(source_array[i-j] != EMPTY_VALUE)
+                 {
+                  sum+=source_array[i-j];
+                  count++;
+                 }
+              }
+            if(count > 0)
+               dest_array[i]=sum/count;
+           }
+         break;
+        }
+     }
+  }
+
+//+------------------------------------------------------------------+
+//|                                                                  |
+//+------------------------------------------------------------------+
+bool CPVINVICalculator::PrepareSourceData(int rates_total, const double &open[], const double &high[], const double &low[], const double &close[])
+  {
+   ArrayResize(m_price, rates_total);
+   ArrayCopy(m_price, close, 0, 0, rates_total);
+   return true;
+  }
+
+//+------------------------------------------------------------------+
+//|                                                                  |
+//+------------------------------------------------------------------+
+bool CPVINVICalculator_HA::PrepareSourceData(int rates_total, 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);
+
+   ArrayResize(m_price, rates_total);
+   ArrayCopy(m_price, ha_close, 0, 0, rates_total);
+   return true;
+  }
+//+------------------------------------------------------------------+
+//+------------------------------------------------------------------+