J-Quants Data Storage and Reproducible Research

Reproduction requires matching input content, selection rules, transformations and software versions. A matching filename and date range do not prove that the experiment used identical observations.

If a fictional price file receives one corrected row, identify the new input separately. Preserve acquisition time and distinguish source input, research transformation and output.

Record API version, endpoint, query selection, acquisition time, schema and counts. Partial or failed acquisitions should remain distinguishable from completed input.

If the last two days of a fictional ten-day request fail, eight days must not be registered as complete. Reconcile completion records with actual observations and identify retries separately.

Renaming columns, interpreting dates, scaling units and handling duplicates can affect results. Preserve transformation recipes and connect them to identified inputs and outputs.

A fictional V1-to-V2 adapter needs semantic mapping, not just name substitution. Compare counts, dates, missingness and units before and after conversion.

Hashes help detect content differences but do not establish correctness or historical availability. Pair input hashes with settings, software identity, logs and output receipts.

Two fictional files can encode the same observations in different order or format and have different byte hashes. Distinguish byte identity from observation equivalence and never reuse another run's identity.

KabuForge's public course validates, freezes and reverifies selected local input. Cache and downstream research can bind different manifests even when selected observations match.

Use the receipt belonging to each operation and follow applicable storage and sharing terms. Matching computation and proving historical availability are separate verification outcomes.

Continue with What Is J-Quants? Research Uses and Limits, Financial Data: Periods and Units, J-Quants and Point-in-Time Research 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 JPX: V2 and delivery-format update, J-Quants: official client usage guide 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

• What to check first in J-Quants price data
• Use J-Quants Data in KabuForge: Your First Research Run
• What Is J-Quants? Research Uses and Limits