# Google Trends Market Sentiment Analysis Tool

## Overview
Traditional market data captures what has happened, but rarely explains *why* or what happens next. This project introduces a systematic framework that leverages alternative data—specifically online search volumes via Google Trends—as a leading indicator for tactical asset allocation and risk control. 

By analyzing real-time shifts in collective investor attention, the tool quantifies market psychology before it fully materializes into trading decisions.

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## The Core Scaling Challenge & Solution

> **The Problem:** Google Trends normalizes search volume to a relative $0 \text{ to } 100$ scale *per individual request*. This makes it statistically impossible to directly compare or chain together data from different batch requests.
>
> **The Algorithmic Solution:** This script implements an **"Anchor-Logic"** to establish a unified global scale. Every automated batch request includes a high-volume, neutral reference term (configurable via `--anchor`, default: `'weather'`). The pipeline then dynamically rescales parallel batches using the **median ratio** of the overlapping anchor series:
>
> $$\text{Scaling Factor} = \text{median}\left(\frac{\text{Anchor}_{\text{Target Batch}}}{\text{Anchor}_{\text{Reference Batch}}}\right)$$
>
> This technique achieves true cross-batch comparability across independent API calls.

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## Methodology & Pipeline Architecture

The prototype (`google_trends_sentiment_prototype.py`) is structured as a modular quantitative pipeline:

### 1. Data Ingestion (Anchor-Based)
Automated retrieval of pre-defined Risk-On, Risk-Off, and Macroeconomic keywords via the `pytrends` API, structurally unified globally using the Anchor-Logic described above.

### 2. Normalization Layer
Applies a **Z-score transformation** to the rescaled raw data. This establishes statistical parity across keywords with vastly different structural search volumes by centering the mean at $0$ and scaling variance to $1$:

$$z = \frac{x - \mu}{\sigma}$$

Where:
* $x$ is the anchor-adjusted search volume intensity.
* $\mu$ is the historical mean of that specific keyword series.
* $\sigma$ is the historical standard deviation of the series.

### 3. Index Construction & Signal Extraction
* **Sentiment Spread:** Measures the relative strength of optimism versus pessimism in the market:
    $$\text{Sentiment Spread} = \left( \frac{1}{N} \sum_{i=1}^{N} z_{\text{Risk-On}, i} \right) - \left( \frac{1}{M} \sum_{j=1}^{M} z_{\text{Risk-Off}, j} \right)$$
* **Macro PCA Factor:** Extracts the first principal component ($PC_1$) from the combined Z-score feature matrix using Singular Value Decomposition (SVD) via `scikit-learn`:
    $$\mathbf{Z} = \mathbf{U}\mathbf{\Sigma}\mathbf{V}^T \implies PC_1 = \mathbf{Z}\mathbf{v}_1$$
    This isolates the dominant underlying psychological driver capturing the highest common variance.

### 4. Market Validation (Optional)
Resamples the extracted signals to a weekly frequency and performs quantitative correlation analysis against live financial benchmarks using `yfinance` without compromising the statistical independence of the core signal.

*Note: This prototype currently focuses on contemporaneous correlation as a proof-of-concept. Time horizons and keyword definitions are structurally predefined rather than data-driven optimized.*

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## Getting Started

### Dependencies
Install the required quantitative stack:
```bash
pip install pytrends pandas numpy scikit-learn yfinance matplotlib