How to Track Amended Filings and Their Impact on Your Analysis
Learn to link amended disclosures to the originals and reasons for revision, then update your analysis. Manage versions for current judgments and for reconstructing past decisions.
When tracking amended disclosures, record the original, reason for amendment, and changed items together rather than replacing only the latest figures. Reflect revised facts in current analysis, while preserving information available at the time when reviewing past decisions. Not every amendment has the same significance.
Distinguish finding the final version from investigating changes
Finding the currently finalized document and identifying what changed historically require different search settings. The OpenDART disclosure search guide distinguishes an option for final reports only from submission histories that include amendments. After checking the latest information, find earlier filings as well if you need to investigate the changes. First match the company, report type, and reference period, then record receipt identifiers. Do not assume several similarly titled documents are all amendments to the same report; check the amendment target and document relationships shown in the originals.
Separate typos from changes that affect analysis
Classifying amendments by dates, amounts, contract terms, or accounting explanations helps prioritize review. If an amount changed, assess its effect on related margins and growth rates; if a contract period changed, review assumptions about revenue timing. Changes in explanatory wording can alter rights or conditions, so comparing numbers alone is insufficient. Avoid assuming misconduct before reading the reason for amendment. Conversely, do not ignore a change because the amount seems small; assess whether it affects a condition central to your investment thesis.
Connect source revisions to model revisions
Changing only the cell containing a revised figure can leave summaries or charts citing the old value. Follow the path from source data through calculation sheets and charts to conclusions. Record before-and-after values, the date applied, and affected conclusions in the change log. When reviewing the appropriateness of a past judgment, do not insert later amendments as though they were already known. A current time series standardized to revised figures and a reconstruction using information available at the time serve different purposes; distinguish them in filenames and explanations.
Worked example
Hypothetical example: Suppose revenue is amended from 1,000 to 900, while operating profit remains 90, all in units of KRW 100 million. The operating margin changes from 9% to 10%. The lower revenue and higher margin result from the amendment, so do not describe this as an actual operating improvement. Review the revised growth rates, ratios, and summaries together, and record the reason for amendment separately. The process must update calculations without automatically making the economic interpretation more optimistic.
What to check
- Have you matched the reference periods of the original and amendment?
- Have you read the reason for amendment and changes in conditions?
- Have you checked ratios, charts, and statements linked to revised values?
- Have you distinguished current judgment from reconstruction of information available at the time?
Sources and primary materials
This is educational material about research methods. For an actual company decision, verify the filings and primary sources for the relevant period.