Historical prices: splits, dividends and missing candles
Before comparing charts, check whether similar column names actually represent the same data.
A historical price series reflects choices of instrument, provider, calendar and adjustment rules. Two charts with the same label can contain different sequences, so preserve data provenance first.
Share price versus the value of ownership
In a hypothetical 2-for-1 split, one share at 100 becomes two at 50. The holding remains worth 100 if nothing else changes. An unadjusted series of 100 → 50 resembles a 50% loss even though the share count doubled.
In a separate simplified example, a share at 100 distributes a cash dividend of 2: a price of 98 plus cash of 2 totals 100 before taxes and costs. This is an accounting illustration, not a guarantee of the actual market-price move on an ex-dividend date.
Do not mix adjustment bases
A provider may adjust history for splits, dividends or both. An adjusted-close column does not necessarily mean that open, high and low were adjusted identically. Read the documentation for the specific series.
For an OHLC calculation, check that all four prices use a consistent basis. Do not silently combine adjusted close with raw H and L. Keep the original file separate from transformations and record each operation.
Our own teaching example; all figures are hypothetical.
| Event | Before | After, without other changes |
|---|---|---|
| 2-for-1 split | 1 share × 100 = 100 | 2 shares × 50 = 100 |
| Dividend of 2 | 1 share × 100 = 100 | 1 share × 98 + 2 cash = 100 |
A missing bar is not always an error
A holiday, a closed session and a missing provider record are different cases. Check the calendar, timezone, regular versus extended session, duplicate timestamps and whether the last bar is complete. Do not invent OHLC without labeling it.
Before importing, retain symbol and exchange, currency, date range, interval, source, download date and adjustment policy. If charts differ, compare one specific candle first. Then use the CSV guide for reproducible Pro input.
Can adjusted close and raw H/L in one CSV automatically be treated as a consistent candle?
No. Establish the provider’s rules and use one explicitly chosen basis for OHLC, or obtain a consistent raw series.
Sources
- Investor.gov · Stock Split
- Investor.gov · Ex-Dividend Dates
- TradingView · How to adjust data for dividends
- Alpha Vantage · Daily Adjusted documentation
Sources checked: 2026-10-20
This material and its translations were prepared with AI assistance. Educational calculations were checked programmatically. Sources explain concepts; examples and files were created for this article.
Related reading
Next step
Check the TradingView CSV import rules for Pro. A prepared series supports a reproducible calculation but does not validate a scenario.
Import TradingView CSV into Pro →