Factor Library – TEJ's Factor Database for Quantitative Investing

Introduction

Over the past decades, quantitative investing has evolved from academic theory into a core pillar of modern investment management. Foundational models such as CAPM, APT, and the Fama-French multifactor framework have shaped how investors identify and quantify systematic return drivers—known as factors. These factors have since been embedded into institutional workflows, powering everything from alpha generation to portfolio construction and risk management.

However, the proliferation of factors—often inconsistently defined or statistically fragile—has given rise to what researchers call the “factor zoo.” This phenomenon underscores the urgent need for structured, high-quality data and disciplined implementation frameworks.

TEJ’s Factor Library was created in response to these challenges. It offers a robust, point-in-time (PIT) database featuring more than 100 academically grounded and locally adapted factors across 9 core categories. Built for practical deployment in the Taiwan stock market, the library empowers investors to accelerate research, build repeatable quantitative strategies, and generate more reliable alpha signals through transparent and consistent data.

Yet even with a well-structured foundation, factor investing remains a complex discipline—especially when moving from theory to execution.

Challenges in Factor Investing

The factor investing process—from data collection to strategy construction—is complex and resource-intensive (see Figure 1). Analysts must source data from multiple providers or crawlers, deal with inconsistent formats, and often face the lack of a point-in-time (PIT) structure—introducing risks like look-ahead bias.

Figure1:Traditional Factor Research Workflow

Preprocessing involves missing value handling, outlier detection, and aligning data by release timing—all technically demanding tasks. Designing factor logic requires extensive literature review, adapting definitions for local markets, and ensuring statistical validity. These challenges consume significant time and resources and introduce errors that can hinder research and replication.

A well-structured factor database that incorporates PIT processing, academic rigor, and transparent methodology can greatly streamline the process and help investors focus on strategy innovation.

Introduction to the Factor Library

TEJ’s Factor Library is a structured, point-in-time database designed to explain asset risks and returns through factor characteristics. It currently covers nine major factor categories: Momentum, Dividend Yield, Value, Growth, Quality, Liquidity, Volatility, Size, and Sentiment. All data are processed with complete PIT alignment and traceability to eliminate forward-looking bias.

Figure 2:TEJ Factor Library -9 Factor Categories

Figure 2:TEJ Factor Library -9 Factor Categories

Database Construction Methodology:

  • Academic Foundations: Derived from global academic journals and institutional research, supplemented by TEJ’s proprietary analysis.
  • Data Source: Built on TEJ’s investment-grade database, fully point-in-time.
  • Localization: Adjusted from academic definitions for relevance to Taiwan’s stock market.
  • Factor Count: Over 100 factors will be built by 2025, including academic and machine-learning-based factors.

New Development Directions (2025 Onward):

  • Machine Learning Factors: Combining supervised and unsupervised algorithms to improve predictive power and local market fit.
  • Alternative Data Factors: Transforming non-traditional sources like news and ESG disclosures into investment-grade factors to diversify strategies and manage risk.                   
CategoryDescription
MomentumReflects the continuation of a company’s stock price and fundamental performance. Includes two subcategories: Price Momentum and Fundamental Momentum.
Dividend YieldReflects a company’s dividend policy.
ValueReflects market valuation of the company. Includes two subcategories: Book-to-Price and Earnings Yield.
GrowthReflects a company’s earnings growth potential.
QualityReflects the fundamental characteristics of a company. Includes subcategories such as Profitability, Earnings Quality, Investment Quality, Earnings Variability, and Solvency.
LiquidityReflects the activeness of stock trading.
VolatilityReflects the uncertainty in stock prices or returns. Includes two subcategories: Beta and Residual Volatility.
SizeReflects the market capitalization of a company.
SentimentReflects investor perception and market sentiment toward a stock. Includes subcategories such as Fund Flow, Holdings, News-based Information, and Behavioral Factors.
Table 1: Description of the 9 Categories in the Factor Library

Factor Library – Use Cases and Applications

The value of the Factor Library extends beyond data provision—it enables diverse applications across the investment lifecycle. Depending on the strategy, investors can deploy single or multiple factors for stock selection, risk assessment, and model construction.

Key Applications

  • Factor-Based Stock Selection: By filtering stocks based on one or multiple factor metrics, investors can identify equities with specific desired characteristics. This helps narrow down the investable universe and improves the precision and efficiency of the stock selection process.
  • Quantitative Investing: Researchers can use factor data to develop entirely new investment strategies or refine existing ones. By integrating selected factors into systematic models, they can better capture specific risk premia and alpha signals—ultimately enhancing portfolio return potential.
  • Risk Analysis: Factor data can be used to assess the underlying risk profile of individual securities or entire portfolios. This enables investors to strengthen their risk control frameworks and make more informed asset allocation decisions.

Example: Multi-Factor Stock Selection

  • Stock Universe Definition: Based on liquidity and size.
  • Factor Testing & Selection: Identify effective factors.
  • Model Construction: Standardize and weight selected factors (e.g., Z-score method).
  • Strategy Execution: Define rebalancing and portfolio rules; execute trades accordingly.

Figure 3: Cumulative Return of a Factor Strategy – highlighting how factor data supports performance backtesting to discover alpha-generating strategies.

Key Benefits of TEJ Factor Library

In today’s market environment—characterized by an explosion of factors and widening information gaps—researchers often find themselves bogged down by labor-intensive processes such as data preparation, validation, and ongoing maintenance. These challenges make it difficult to focus on strategic optimization and backtesting. The TEJ Factor Library was explicitly designed to solve these pain points. Its data service emphasizes academic rigor, practical relevance, and completeness in update frequency, data structure, and usability. It also serves as a high-quality market data service that facilitates advanced quantitative data analysis.

Feature

  • Delivers daily updated factor data
  • Built on a full Point-in-Time (PIT) architecture, covering a wide range of factor categories
  • All factor calculations are academically grounded, accompanied by clear documentation (Table 2)
  • Offers transparent and traceable data processing workflows

Advantage

  • Reduces research time and lowers the risk of data-related errors
  • Enhances the robustness of strategies and the credibility of backtest results

Benefit

  • Accelerates research cycles and improves development productivity
  • Effectively supports the deployment of quantitative strategies in real-world applications
Factor Codemom52wh
Factor NameMomentum Factor (52-Week High)
English Name52-Week High Momentum (MOM52WH)
CategoryMomentum
SubcategoryPrice Momentum
Expected DirectionPositive
ReferenceGeorge, T.J., & Hwang, C. (2004). The 52-Week High and Momentum Investing. Journal of Finance, 59(5), 2145–2176.
Calculation MethodAdjusted closing price of the day divided by the highest adjusted price over the past 252 trading days.
Table 2: Sample Factor Description

Conclusion

TEJ’s Factor Library empowers investment teams with high-quality, standardized, and traceable factor data, bridging the gap from data acquisition to live strategy execution. It’s not just a research tool, but a strategic asset—enabling alpha discovery, model backtesting, and risk management.

By combining academic insights with local market practices, and supporting over 100 factors across nine categories with PIT structure and daily updates, TEJ provides the robust infrastructure required to navigate the expanding world of factor investing. In an era of market uncertainty and data explosion, only those with access to verifiable and flexible factor systems can stay ahead in the quant investing landscape.

TEJ’s commitment to innovation, accuracy, and usability positions the Factor Library as an indispensable resource for investors aiming to transform data into performance.

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