J-Quants and Point-in-Time Research

Point-in-time research checks whether every input was available by the corresponding decision cutoff. Downloading historical values today does not complete that check.

For a fictional Monday opening decision, information published later on Monday is unavailable. Same-date joins need a cutoff rule rather than an assumption that every daily value was already known.

Separate observation or period end, public disclosure and arrival in the research environment. A Date field in different datasets can represent different clocks.

For a fictional financial join, record the first eligible decision and supporting timing evidence. Keep unknown arrival times separate from assumed delays so assumptions remain inspectable.

Applying latest corrected values or current classifications to the past can change the information set. Retaining versions and selecting eligible versions are separate responsibilities.

If a fictional security later moves market segments, current and historical membership rules produce different samples. Track both value versions and universe definitions.

Using prior-observation prices helps avoid same-session future values. It does not certify financial revisions, classifications, adjustment histories or delivery timing.

A fictional one-day lag cannot repair a correction issued weeks later. Lag sensitivity is an experimental assumption, not a substitute for missing historical availability evidence.

The public KabuForge course separates decisions and execution but explicitly retains pit_guarantee=false. Reproducible historical computation is not a full historical availability guarantee.

List verified and unknown clocks for each input. Check feature ingredients and universe selection before describing a study as point-in-time verified.

Continue with Factor Analysis: Inputs and Evaluation, Data Storage and Reproducible Research, Disclosure Times and Financial Revisions to connect input definitions, availability and evaluation. All numerical and company examples in this article are fictional teaching examples. For real input, prioritize the documentation for your version and your own acquisition and execution records.

Check the official KabuForge GUI research course for documented workflow scope, and J-Quants: official V2 financial implementation, J-Quants: official V2 equities implementation for provider documentation or current official implementation. Confirm exact units and access limits against the applicable official specification and contract. General research design guidance does not establish that every proposed check is implemented in the GUI.

This article is educational and does not recommend securities or trades, or guarantee returns. Historical research in the public course does not fully establish that only historically available information was used. Read the disclaimer.

Explore the j-quants learning path

• Factor Analysis with J-Quants Data: Inputs and Evaluation
• J-Quants Listed Issues and Market Segments
• J-Quants Data Storage and Reproducible Research