Why Adjusted Historical Stock Prices May Differ from Market Prices

Summary

This discussion raises a data-reconciliation question: why historical prices retrieved from a Chinese equity data platform still differ from observed market prices after dividing open, high, low, and close by an adjustment factor. The example queries daily bars for one stock and date range through two platform interfaces, applies the same transformation, and compares a selected date.

The document contains no answer or confirmed cause; it consists of the question and code used to investigate it. It therefore does not establish whether the discrepancy comes from adjustment-factor conventions, reference-price definitions, corporate actions, or another data issue. Its value is as a reproducible prompt for checking price-adjustment methodology and data-source consistency, rather than as guidance that resolves the discrepancy.

Key ideas

• The author reports that reversing an adjustment factor did not make historical OHLC prices match the expected market prices.
• The same stock and date range were queried through two interfaces to compare the returned data.
• The document does not identify the cause or provide a verified resolution to the discrepancy.
• Adjustment conventions and source data would need to be investigated before using the transformed prices.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.