The Scenario
A new analyst joined the team last month, inherited a portfolio model, and sent a message this morning: the historical return calculations are wrong for three positions because the prices don't account for stock splits. You know exactly what happened — the model was built without split adjustments. Now you need every split event for 15 tickers going back as far as Polygon has records, written into a reference tab so the backward adjustment can be applied properly.
The bad version:
- Open Polygon's splits endpoint for the first ticker, get the list of split events.
- Copy the ex-date, the split ratio (from/to), and the payment date into a sheet.
- Repeat for 14 more tickers, being careful to note whether each ratio is expressed as a multiplier or a fraction.
- Realize two tickers have splits from before 2010 that require a different date format to pull correctly.
- Rebuild those two, double-check that the ratio direction is consistent, then update the model with the reference data.
The model was broken at 9 AM. It's now 11:30 AM and you've fixed one of the three problem positions.
The Easy Way: One Prompt in SheetXAI
SheetXAI is an AI agent inside your Google Sheet that connects to Polygon's corporate actions endpoints and pulls the full split history across your ticker list in one pass.
For each ticker in column A, fetch all historical stock splits from Polygon and write the ex-date, split ratio, and payment date into columns B, C, and D.
What You Get
- One row per split event per ticker, with columns: Ticker, Ex-Date, Split Ratio (formatted as from:to, e.g., 1:4 for a 4-for-1 split), Payment Date.
- Ratio expressed consistently as a multiplier (e.g., 4.0 for a 4-for-1) in a fifth column if needed for calculations.
- Events sorted by ex-date ascending within each ticker block.
- Tickers with no split history noted with a single row containing "No splits found."
What If the Data Is Not Quite Ready
I need the data in a log format across all tickers, not grouped by ticker
Pull the complete stock split history from Polygon for every ticker in column A and write each split event into a Splits Log tab with columns: Ticker, Ex-Date, From Shares, To Shares — all tickers interleaved, sorted by ex-date ascending.
I want to apply the splits to my existing price column automatically
For each ticker in column A, fetch all stock splits from Polygon, then for each close price in column C that is dated before a split ex-date, adjust the price by the cumulative split ratio and write the adjusted price into column D.
I only need splits from the last 5 years
For each ticker in column A, pull stock splits from Polygon that occurred after January 1, 2020, and write ex-date and split ratio into columns B and C.
Flag any ticker that has had more than one split, note the cumulative adjustment factor, and highlight those rows
For each ticker in column A, fetch all historical splits from Polygon, calculate the cumulative price adjustment factor, flag any ticker with more than one split in column D, and highlight those rows in orange for manual review.
The combined pull and calculation saves the separate step of deriving adjustment factors after the fact.
Try It
Get the 7-day free trial of SheetXAI and open any portfolio model in Google Sheets, then ask it to pull the full stock split history from Polygon for your position list. You might also want to pull historical OHLCV data alongside the split history to build a fully adjusted price series.