Value investing: separate valuation measures from future returns

A low share price alone does not establish cheapness. Shares outstanding and company size differ. A value study first chooses a measure of fundamentals relative to price. This article uses book equity divided by market capitalization.

The ratio describes a characteristic, rather than proving intrinsic value or guaranteeing a subsequent gain.

EX-A has book equity of 10 billion yen and market capitalization of 20 billion. EX-B has book equity of 8 billion and market capitalization of 8 billion. Their book-to-market ratios are 0.5 and 1.0. These are fictional teaching inputs.

The reciprocal price-to-book ratios are 2 and 1. Specify the ranking direction. Zero or negative book equity requires a separate eligibility rule.

A balance sheet date is not its publication date. Record releases and revisions, and use only values available before the decision. Filling history with the latest revised accounts changes the information set.

Define sector comparisons and exclusions before evaluating returns. Report missing and nonpositive book equity counts because exclusions change the sample.

A high ratio may reflect concerns about future business conditions or asset write-downs. Check sector concentration and the treatment of delisted firms. A ranking alone cannot establish why subsequent returns occurred.

An academic value factor is a portfolio return series. It is different from a company characteristic, and from the return of a long-only high-ratio group.

KabuForge’s public course separates momentum features from future-return labels and examines correlations and quantiles. It offers a research workflow, without establishing a built-in book-to-market strategy or automatic financial-data import.

Define the required inputs and historical availability first. Read factors, point-in-time data and quantile analysis.

Concept references: Fama–French factor construction. Additional reference: value classification within the five-factor construction. Software workflow and limitations: KabuForge public GUI research course. Reviewed October 6, 2026. The fictional examples are teaching calculations, not course execution results.

The public course is research-only and does not certify historical information availability. A concept explanation does not establish that every method is implemented in the software. This article recommends no securities, trades or settings. Read the disclaimer.

Explore the strategy concepts learning path

• Quality factors: fix a profitability definition before comparing firms
• Size factors: distinguish market capitalization from a return spread
• Low volatility: measure historical variation without promising safety