diff --git a/Indicators/MyIndicators/VIDYA_TrendActivity_Pro.md b/Indicators/MyIndicators/VIDYA_TrendActivity_Pro.md
new file mode 100644
index 0000000..a7ef79c
--- /dev/null
+++ b/Indicators/MyIndicators/VIDYA_TrendActivity_Pro.md
@@ -0,0 +1,61 @@
+# VIDYA Trend Activity Professional
+
+## 1. Summary (Introduction)
+
+The VIDYA Trend Activity is a custom-built "meta-indicator" designed to measure the directional strength and activity of the **Variable Index Dynamic Average (VIDYA)**. While the VIDYA line itself shows the trend, this oscillator quantifies *how trendy* the market is according to the VIDYA's behavior.
+
+Its primary purpose is to act as a **trend filter**. It generates high values when the VIDYA is moving decisively and low values when the VIDYA line flattens out.
+
+Our `VIDYA_TrendActivity_Pro` implementation is a unified, professional version that allows all underlying calculations (both VIDYA and ATR) to be based on either **standard** or **Heikin Ashi** data.
+
+## 2. Mathematical Foundations and Calculation Logic
+
+This indicator analyzes the behavior of two underlying indicators, VIDYA and ATR, to produce a final, normalized oscillator.
+
+### Required Components
+
+* **VIDYA:** The underlying adaptive moving average. Its slope is the primary input.
+* **ATR (Average True Range):** Used as a normalization factor.
+* **Smoothing Period:** A final smoothing period for the oscillator output.
+
+### Calculation Steps (Algorithm)
+
+1. **Calculate VIDYA:** First, the standard VIDYA is calculated.
+2. **Calculate ATR:** Separately, the standard Wilder's ATR is calculated.
+3. **Calculate Raw Activity:** For each bar, the indicator measures the rate of change of the VIDYA line and normalizes it by the market's current volatility (ATR).
+    $\text{Raw Activity}_i = \frac{\text{Abs}(\text{VIDYA}_i - \text{VIDYA}_{i-1})}{\text{ATR}_i}$
+4. **Normalize with Arctan:** The `Raw Activity` value is passed through the inverse tangent (`Arctan`) function and scaled to a consistent `0..1` range.
+    $\text{Scaled Activity}_i = \frac{\text{Arctan}(\text{Raw Activity}_i)}{\pi/2}$
+5. **Final Smoothing:** The `Scaled Activity` values are smoothed with a Simple Moving Average (SMA).
+    $\text{Final Activity}_i = \text{SMA}(\text{Scaled Activity}, \text{Smoothing Period})_i$
+
+## 3. MQL5 Implementation Details
+
+Our MQL5 implementation follows a modern, component-based, object-oriented design.
+
+* **Component-Based Design:** The `VIDYA_TrendActivity_Calculator` **reuses** our existing, standalone `VIDYA_Calculator.mqh` and `ATR_Calculator.mqh` modules. This eliminates code duplication and ensures consistency.
+
+* **Object-Oriented Logic:**
+  * The `CVIDYATrendActivityCalculator` base class contains pointers to the VIDYA and ATR calculator objects.
+  * The Heikin Ashi version (`CVIDYATrendActivityCalculator_HA`) is achieved simply by instantiating the Heikin Ashi version of the VIDYA module (`CVIDYACalculator_HA`). The ATR calculator type is chosen dynamically based on user input.
+
+* **Stability via Full Recalculation:** We employ a "brute-force" full recalculation within `OnCalculate` for maximum stability.
+
+## 4. Parameters
+
+* **VIDYA Settings:**
+  * `InpPeriodCMO`: The period for the underlying Chande Momentum Oscillator.
+  * `InpPeriodEMA`: The base period for the underlying VIDYA.
+  * `InpSourcePrice`: The source price for the underlying VIDYA. This unified dropdown allows you to select from all standard and Heikin Ashi price types.
+* **Activity Calculation Settings:**
+  * `InpAtrPeriod`: The period for the ATR used in normalization.
+  * `InpAtrSource`: Determines the source for the ATR calculation (`Standard` or `Heikin Ashi`).
+  * `InpSmoothingPeriod`: The period for the final SMA smoothing of the oscillator.
+
+## 5. Usage and Interpretation
+
+* **Trend Filter:** This is the indicator's primary function. A trader can establish a threshold (e.g., 0.1 or 0.2).
+  * **Activity > Threshold:** The market is considered to be in a **trending phase**.
+  * **Activity < Threshold:** The market is considered to be in a **ranging or consolidating phase**.
+* **Identifying Trend Exhaustion:** A sharp decline in the activity histogram after a strong trend can signal that momentum is waning.
+* **Confirming Breakouts:** A spike in the activity histogram accompanying a price breakout can provide strong confirmation that the breakout has momentum.