SPY Stock Price Prediction with Gradient Boosting

A machine learning project that predicts SPY (S&P 500 ETF) price movements over the next 3 days using gradient boosting models (XGBoost, LightGBM, CatBoost) trained on 115 engineered features from technical indicators, volume patterns, and cross-asset relationships.

🎯 Project Overview

This project implements a comprehensive machine learning pipeline for predicting whether SPY will move up or down over the next 3 trading days. The pipeline includes:

• Data Collection: Automated download of OHLCV data for SPY, VIX, TLT, DXY, and GLD
• Feature Engineering: 115 technical indicators across 5 feature modules
• Model Training: Three gradient boosting algorithms with 2-phase training (all features → selected features)
• Model Evaluation: Comprehensive performance analysis and comparison
• Production Ready: Model loading and prediction examples

📊 Key Results

Model	Test ROC AUC	Test Accuracy	Status
LightGBM (40 features)	0.5546	60.54%	✅ Best
CatBoost (40 features)	0.4953	59.77%	⚠️ Decent
XGBoost (40 features)	0.4750	58.62%	⚠️ Decent
Ensemble (soft voting)	0.4857	55.17%	❌ Worse

Winner: LightGBM with 40 selected features achieves the best performance.

🗂️ Project Structure

stockprediction/
├── README.md                          # This file
├── download_data.py                   # Data download script
├── download_data.md                   # Data download documentation
├── feature_engineering.py             # Main feature engineering pipeline
├── FEATURE_MODULES_README.md          # Feature engineering documentation
├── spy_xgboost_features.md            # Feature specifications
│
├── Feature Modules/
│   ├── price_based_features.py        # Price, momentum, MA features
│   ├── volume_features.py             # Volume-based features
│   ├── volatility_features.py         # Volatility and technical indicators
│   ├── cross_asset_features.py        # VIX, TLT, DXY, GLD features
│   └── regime_dependent_features.py   # Market regime features
│
├── Model Training Scripts/
│   ├── modelling_xgboost.py           # XGBoost training
│   ├── modelling_lightgbm.py          # LightGBM training (BEST)
│   ├── modelling_catboost.py          # CatBoost training
│   └── modelling_ensemble.py          # Ensemble model
│
├── modelling.md                       # Model results & usage guide
│
└── output/
    ├── spy_features_full.csv          # Generated features
    └── models/
        ├── xgboost/                   # XGBoost models & metrics
        ├── lightgbm/                  # LightGBM models & metrics ⭐
        ├── catboost/                  # CatBoost models & metrics
        └── ensemble/                  # Ensemble model & metrics

📚 Documentation

• download_data.md - Data collection and preparation
• FEATURE_MODULES_README.md - Feature engineering details
• spy_xgboost_features.md - Feature specifications
• modelling.md - Model comparison, results, and usage guide

🚀 Quick Start

1. Installation

# Clone the repository
git clone https://github.com/yourusername/stockprediction.git
cd stockprediction

# Create virtual environment
python -m venv .venv
source .venv/bin/activate  # On Windows: .venv\Scripts\activate

# Install dependencies
pip install pandas numpy yfinance ta-lib
pip install xgboost lightgbm catboost
pip install scikit-learn matplotlib seaborn

2. Download Data

# Download OHLCV data for SPY, VIX, TLT, DXY, GLD (2015-present)
python download_data.py

See download_data.md for details.

3. Generate Features

# Run feature engineering pipeline (creates 115 features)
python feature_engineering.py

Output: output/spy_features_full.csv

See FEATURE_MODULES_README.md for feature details.

4. Train Models

# Train LightGBM (recommended)
python modelling_lightgbm.py

# Or train all models
python modelling_xgboost.py
python modelling_catboost.py
python modelling_ensemble.py

Models saved to output/models/{model_name}/

5. Make Predictions

import lightgbm as lgb
import pandas as pd

# Load best model
model = lgb.Booster(model_file='output/models/lightgbm/lightgbm_model_selected_features.json')

# Load required features
with open('output/models/lightgbm/selected_features.txt', 'r') as f:
    required_features = [line.strip() for line in f.readlines()]

# Load your data
df = pd.read_csv('output/spy_features_full.csv')
df['Date'] = pd.to_datetime(df['Date'])
df.set_index('Date', inplace=True)

# Get latest data
latest = df[required_features].iloc[-1:]

# Predict
prob_up = model.predict(latest)[0]
prediction = "Up" if prob_up > 0.5 else "Down"

print(f"Prediction: {prediction}")
print(f"Probability: {prob_up:.2%}")

See modelling.md for complete usage guide.

🔧 Features

Feature Categories (115 total)

1. Price-Based Features (19 features)

   • Momentum indicators (3d, 5d, 10d, 20d, 50d)
   • Moving averages (20, 50, 100, 200-day)
   • Price extremes and gaps

2. Volume Features (16 features)

   • Volume ratios and z-scores
   • Volume trends and spikes
   • Accumulation/distribution patterns

3. Volatility Features (30 features)

   • ATR, Bollinger Bands, RSI, MACD
   • Volatility regimes
   • Technical indicator combinations

4. Cross-Asset Features (35 features)

   • VIX (volatility index) features
   • TLT (bonds), DXY (dollar), GLD (gold)
   • Risk-on/risk-off regimes

5. Regime-Dependent Features (15 features)

   • Market regime detection
   • Hurst exponent (trend persistence)
   • Regime-specific indicators

Top 6 Most Important Features

1. spy_volume_ratio_50d - 50-day volume ratio
2. spy_rsi_14 - 14-day RSI
3. spy_macd_pct - MACD percentage
4. spy_volume_ratio_20d - 20-day volume ratio
5. spy_momentum_3d - 3-day momentum
6. vix_spy_ratio - VIX to SPY ratio

📈 Model Training Approach

Two-Phase Training

Phase 1: All Features (115)

• Train with all engineered features
• Calculate permutation importance on test set
• Identify truly predictive features

Phase 2: Selected Features (40)

• Retrain with top 40 features from permutation importance
• Reduce overfitting and improve generalization
• Compare performance vs full model

Models Evaluated

1. XGBoost: Level-wise tree growth with aggressive regularization
2. LightGBM: Leaf-wise tree growth with default parameters ⭐
3. CatBoost: Ordered boosting with symmetric trees
4. Ensemble: Soft voting (probability averaging) of all three

📊 Performance Analysis

LightGBM (Best Model)

Metrics (Test Set: 2025-01-02 to 2026-01-16):

• ROC AUC: 0.5546
• Accuracy: 60.54%
• Precision (Up): 61%
• Recall (Up): 96%
• F1 Score: 0.7469

Characteristics:

• High recall for "Up" predictions (catches most upward movements)
• Low precision for "Down" predictions (many false alarms)
• Stopped at iteration 3 (aggressive early stopping)
• Best generalization with feature selection

Key Insights

1. Volume features are most predictive across all models
2. Feature selection significantly improved LightGBM (+7.46% ROC AUC)
3. Early stopping was critical for preventing overfitting
4. Market regime shifts impact model performance (train: 2015-2023, test: 2024-2026)
5. Limited predictive power for 3-day movements (best AUC ~0.55)

⚠️ Important Notes

Model Limitations

• Not recommended for live trading without additional signals
• Performance may degrade with market regime changes
• Best used as one signal among many
• 3-day prediction horizon is inherently challenging

Production Considerations

• Retrain periodically with updated data
• Monitor performance metrics over time
• Implement proper risk management
• Consider ensemble with other strategies

🔄 Retraining Workflow

# 1. Update data
python download_data.py

# 2. Regenerate features
python feature_engineering.py

# 3. Retrain models
python modelling_lightgbm.py
python modelling_xgboost.py
python modelling_catboost.py

# 4. Compare results
# Check output/models/{model_name}/metrics.json

📁 Output Files

Each model generates:

• {model}_model.json - Full model (115 features)
• {model}_model_selected_features.json - Selected model (40 features)
• permutation_importance.csv - Feature importance scores
• selected_features.txt - Top 40 features list
• feature_importance_top30.png - Importance visualization
• permutation_importance_top40.png - Permutation importance plot
• training_curves.png - AUC curves during training
• metrics.json - Performance metrics

🛠️ Technical Stack

• Python: 3.11+
• Data: pandas, numpy, yfinance
• ML: xgboost, lightgbm, catboost, scikit-learn
• Visualization: matplotlib, seaborn
• Technical Analysis: ta-lib

📖 Further Reading

• Feature Engineering Guide - Detailed feature descriptions
• Model Comparison & Usage - Complete model analysis and usage examples
• Data Collection - Data sources and preparation

🤝 Contributing

Contributions are welcome! Areas for improvement:

1. Feature Engineering: Add sentiment data, options flow, market microstructure
2. Model Improvements: Extend prediction horizon, add regime detection
3. Alternative Targets: Predict magnitude of moves, not just direction
4. Ensemble Methods: Weighted voting, stacking, blending

📄 License

This project is for educational purposes. Not financial advice.

🙏 Acknowledgments

• Data provided by Yahoo Finance (yfinance)
• Technical indicators from TA-Lib
• Gradient boosting frameworks: XGBoost, LightGBM, CatBoost

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Last Updated: 2026-01-17

Best Model: output/models/lightgbm/lightgbm_model_selected_features.json