Add Santa Claus Rally executive summaries (English and Czech)

- Create EXECUTIVE_SUMMARY_SANTA_RALLY.md (comprehensive English summary)
- Create EXECUTIVE_SUMMARY_SANTA_RALLY_CS.md (Czech translation)
- Highlight 2 statistically significant DJIA stocks (DIS, JPM)
- Compare Santa Rally vs. Thanksgiving effectiveness
- Include investment strategies and sector analysis
- Document methodology and limitations

Author: lieblm

EXECUTIVE_SUMMARY_SANTA_RALLY.md

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+# Santa Claus Rally: Executive Summary
+
+**Analysis Period:** 2000-2024 (25 years)  
+**Trading Window:** Last 5 trading days of year + First 2 trading days of next year (7 days)  
+**Author:** Martin Liebl (lieblm@gmail.com)  
+**Date:** December 16, 2025
+
+---
+
+## Key Finding: Stronger Than Thanksgiving
+
+The Santa Claus Rally shows **statistically significant evidence** in 2 of 30 DJIA stocks (Disney +2.55%, JPMorgan +1.97%), making it **stronger than the Thanksgiving effect** which showed zero statistically significant stocks after correction. This suggests year-end positioning creates a more reliable seasonal pattern for specific large-cap value stocks.
+
+---
+
+## Cross-Index Results Summary
+
+| Index | Stocks | Observations | Coverage | Significant Stocks | Top Performer |
+|-------|--------|--------------|----------|-------------------|---------------|
+| **DJIA** | 30 | 718 | 95.7% | **2*** | DIS (+2.55%) |
+| **NASDAQ-100** | 73 | 1,898 | 78.8% | 0 | MU (+3.69%) |
+| **S&P 500** | 229 | 5,475 | 88.9% | 0 | CF (+3.84%) |
+
+*Statistically significant after Benjamini-Hochberg FDR correction (α=0.05)
+
+---
+
+## Statistical Significance Winners
+
+### DIS (Walt Disney) ⭐
+- **Median Return:** +2.55%
+- **Win Rate:** 72% (18 of 25 years)
+- **p-value:** 0.037 (significant after correction)
+- **Sharpe Ratio:** 0.631
+- **Sector:** Consumer Discretionary
+
+### JPM (JPMorgan Chase) ⭐
+- **Median Return:** +1.97%
+- **Win Rate:** 72% (18 of 25 years)
+- **p-value:** 0.037 (significant after correction)
+- **Sharpe Ratio:** 0.641
+- **Sector:** Financials
+
+These are the **only two stocks** across all three indices that pass rigorous statistical testing with multiple testing correction.
+
+---
+
+## Pattern Strength by Index
+
+**Positive Median Returns:**
+- DJIA: 86.7% (26 of 30 stocks)
+- NASDAQ-100: 72.6% (53 of 73 stocks)
+- S&P 500: 81.7% (187 of 229 stocks)
+
+**Broad-Based Effect:** Over 80% of stocks show positive median returns in DJIA and S&P 500, suggesting widespread year-end optimism, but concentrated statistical significance.
+
+---
+
+## Top 5 Performers by Index
+
+### DJIA Top 5
+1. **DIS** +2.55% (72% win, p=0.037***)
+2. **JPM** +1.97% (72% win, p=0.037***)
+3. CSCO +1.69% (64% win)
+4. CAT +1.54% (60% win)
+5. INTC +1.49% (56% win)
+
+### NASDAQ-100 Top 5
+1. MU +3.69% (64% win)
+2. ON +2.44% (68% win)
+3. LULU +2.39% (61% win)
+4. AMAT +2.05% (68% win)
+5. CHTR +1.72% (73% win)
+
+### S&P 500 Top 5
+1. CF +3.84% (70% win)
+2. MU +3.69% (64% win)
+3. WMB +3.24% (72% win)
+4. SCHW +3.08% (68% win)
+5. FCX +2.98% (64% win)
+
+---
+
+## Sector Winners
+
+**1. Financials** 🏦
+- JPM, SCHW, COF, AXP all in top performers
+- Payment networks and diversified banks dominate
+- Year-end portfolio rebalancing drives demand
+
+**2. Semiconductors** 💻
+- MU, AMAT, INTC show strong patterns
+- Memory and equipment stocks benefit
+- Tech sector optimism for next year
+
+**3. Consumer Discretionary** 🛒
+- DIS (statistically significant), LULU, ROST
+- Holiday sentiment and retail strength
+- Entertainment and specialty retail lead
+
+**4. Energy** ⚡
+- WMB, VLO, FCX, DVN in S&P 500 top 10
+- Commodity exposure and year-end positioning
+
+---
+
+## Why DJIA Shows Significance (Others Don't)
+
+1. **Multiple Testing Penalty:** DJIA tests 30 stocks vs. 73 (NASDAQ) or 229 (S&P), making statistical significance easier to achieve
+2. **Sample Composition:** Large-cap value stocks more suitable for year-end positioning
+3. **Sector Mix:** DJIA's financials and consumer discretionary align with Santa Rally thesis
+4. **Lower Volatility:** DIS and JPM show consistent returns with favorable risk profiles
+
+---
+
+## Investment Strategies
+
+### Conservative (Highest Confidence)
+**Target:** DIS, JPM only
+- Both statistically significant (p<0.05 after correction)
+- Expected return: ~2.0-2.5% over 7 days
+- Win rate: 72%
+- **Best for:** Risk-averse investors seeking evidence-based positions
+
+### Balanced (Moderate Confidence)
+**Target:** Top 10-15 performers with 65%+ win rates
+- Semiconductors: MU, AMAT
+- Financials: SCHW, COF, AXP
+- Consumer: LULU, ROST
+- Expected return: ~1.5-3.0% over 7 days
+- **Best for:** Active traders with sector diversification
+
+### Aggressive (Pattern-Based)
+**Target:** Sector baskets (Tech, Financials, Energy)
+- Diversified exposure across top performers
+- Expected return: ~1.0-2.5% over 7 days
+- Higher volatility, no statistical guarantee
+- **Best for:** Speculation on seasonal pattern
+
+---
+
+## Comparison: Santa Rally vs. Thanksgiving
+
+| Metric | Santa Rally | Thanksgiving |
+|--------|-------------|--------------|
+| Trading Days | 7 | 4-5 |
+| DJIA Significant Stocks | **2** | 0 |
+| DJIA Top Return | +2.55% (DIS) | +2.00% (AAPL) |
+| DJIA Positive % | 86.7% | 83.3% |
+| Effect Strength | **Stronger** | Moderate |
+
+**Verdict:** Santa Claus Rally provides stronger statistical evidence and may be more reliable for systematic trading strategies.
+
+---
+
+## Methodology
+
+- **Statistical Test:** Wilcoxon signed-rank test (non-parametric)
+- **Multiple Testing Correction:** Benjamini-Hochberg FDR (α=0.05)
+- **Sample Size:** 25 observations per stock (2000-2024)
+- **Return Calculation:** Simple returns (Close/Open - 1) × 100
+- **Data Source:** Yahoo Finance with auto-adjustment
+- **Holiday Calendar:** NYSE with 10 federal holidays
+
+---
+
+## Limitations
+
+1. **Survivorship Bias:** Current index constituents used for historical period
+2. **Sample Size:** 25 years provides limited statistical power
+3. **Multiple Testing:** Severe penalty for broader indices (S&P 500: 229 tests)
+4. **Transaction Costs:** Not modeled; may reduce realized returns
+5. **Market Regime:** 2000-2024 spans multiple cycles (tech bubble, financial crisis, COVID)
+
+---
+
+## Key Takeaways
+
+✅ **Santa Claus Rally is statistically validated** in 2 DJIA stocks (vs. 0 for Thanksgiving)  
+✅ **Broad-based positive pattern** (81.7% of S&P 500 stocks have positive median)  
+✅ **Financials and consumer discretionary lead** with statistical significance  
+✅ **Semiconductors show strong patterns** across all indices  
+✅ **7-day window provides clear entry/exit** for tactical positioning  
+⚠️ **Statistical significance is rare** after proper multiple testing correction  
+⚠️ **No guarantee of future performance** despite historical patterns  
+
+---
+
+## For More Information
+
+- **Full Analysis:** See `ANALYSIS_SANTA_RALLY_COMPARISON.md`
+- **Repository:** https://github.com/lieblm/thanksgiving-alpha
+- **Methodology:** See README.md for technical details
+- **Citation:** See CITATION.cff for academic use
+
+---
+
+**Disclaimer:** This analysis is for educational and research purposes only. Past performance does not guarantee future results. No investment advice is provided. Always consult a financial advisor before making investment decisions.
+
+---
+
+**Contact:** Martin Liebl (lieblm@gmail.com)  
+**License:** MIT  
+**Version:** 1.0 (December 2025)