Walk-Forward Analysis and Overfitting Validation

The structure of walk-forward analysis, the metrics it produces (IS-OOS gap, parameter stability), a momentum-lookback tuning case, and the limits that keep it from being a universal validator.

May 14, 2026 · 5 min read

Korean Account Types and Investment Constraints

The core constraints of the four Korean retail account types — general, ISA, pension savings, and IRP — covering tax-free thresholds, tax deductions, the 70% risk-asset cap, and access to direct foreign investment, plus a strategy-to-account mapping.

May 13, 2026 · 5 min read

Backtest Pitfalls Case Study

Concrete cases of look-ahead bias and survivorship bias — full-period momentum normalization, financial disclosure lag, close-on-close fills, S&P 500 reconstitution, the limits of free APIs — followed by an avoidance checklist.

May 12, 2026 · 5 min read

Efficient Frontier and Portfolio Optimization

Covers Markowitz’s mean-variance model as the mathematical foundation for setting asset weights, the two optimal points on the efficient frontier (Min-Variance and Tangency), and the practical adjustments that compensate for the model’s weaknesses.

May 11, 2026 · 6 min read

Technical Indicators and Trading Signals

Covers technical indicators (RSI, SMA Cross, MACD, Bollinger Bands) for reading price movements, composite signal design, and a comparison of three strategy types across different time horizons.

September 1, 2025 · 5 min read

Portfolio Management and Factor Scoring

Covers factor scoring methods (Z-Score, Rank) for combining indicators into a single score, plus the basics of rebalancing and asset allocation.

August 15, 2025 · 4 min read

Backtest Performance Metrics

Covers the formulas and interpretation of CAGR, MDD, Sharpe Ratio, and other backtest metrics, plus five common backtesting pitfalls.

August 1, 2025 · 4 min read

Momentum and Dividend

Covers the role of price momentum and dividend yield as factors in quant investing.

July 15, 2025 · 4 min read

Valuation and Quality Indicators

Covers how to judge whether a company is cheap (valuation) and whether it earns well (quality) — formulas and interpretation of PER, PBR, PSR, ROE, ROA, and debt ratio.

July 1, 2025 · 5 min read

Stock Data Basics

Covers OHLCV data as the starting point of quant investing, the difference between simple and log returns, and the meaning of market capitalization.

June 15, 2025 · 4 min read