The Scenario
You're a data analyst at a multi-sector equity fund. Your job for today is to build the foundation for a sector heatmap in Google Sheets: every U.S. stock's daily OHLCV for yesterday, classified by sector, so the portfolio team can visualize which sectors outperformed and which lagged. The Polygon.io grouped daily endpoint has exactly what you need. The question is how to get it into the sheet without writing the API call yourself.
The bad version:
- You write a Python script to call the Polygon.io grouped daily API, parse the JSON, and write to a CSV. You spend 20 minutes debugging the authentication headers.
- The CSV has 8,000 rows. You import it into Google Sheets and realize column widths are off and the header row got duplicated somehow. You spend 15 minutes cleaning.
- You add a sector lookup column using a VLOOKUP against a reference tab. Two tickers are missing from your reference table and you don't notice until the PM asks why two cells in the heatmap are blank.
The sheet is the destination. The API call and the cleanup are the overhead nobody budgeted for.
The Easy Way: One Prompt in SheetXAI
SheetXAI is an AI agent that lives inside your Google Sheet. It reads your request, calls the Polygon.io grouped daily endpoint for the date you specify, and writes the full market snapshot directly into a tab — no Python, no CSV, no import.
Fetch the grouped daily OHLCV data from Polygon.io for all U.S. stocks for the trading date in cell A1 and write ticker, open, high, low, close, and volume into a new sheet called "Market Snapshot."
What You Get
- A "Market Snapshot" tab with one row per ticker.
- Columns: Ticker, Open, High, Low, Close, Volume.
- The date sourced from cell A1 — change the date, rerun the prompt, get a fresh snapshot.
- Tickers sorted alphabetically by default so cross-referencing against a sector reference tab is straightforward.
What If the Data Is Not Quite Ready
I also want a percentage change column calculated from open to close
Pull yesterday's full-market daily summary from Polygon.io into my Excel workbook, then add a column that calculates percentage change from open to close for every ticker.
I need to add sector classifications from a reference tab
Fetch the grouped daily OHLCV data from Polygon.io for the trading date in cell A1 and write ticker, open, high, low, close, and volume into the "Market Snapshot" tab. Then add a "Sector" column using a VLOOKUP against the "Sector Reference" tab where column A is ticker and column B is sector name. If a ticker is not found in the reference table, write "Unclassified."
I want a summary tab that shows average daily return by sector
Fetch the grouped daily OHLCV data from Polygon.io for the date in cell A1 and write it into a "Market Snapshot" tab. Add a percentage change column (close minus open, divided by open). Then join against the "Sector Reference" tab to get sector for each ticker and write a "Sector Summary" tab showing each sector's average percentage change for the day, sorted from highest to lowest.
Pull three consecutive trading days of grouped data and show day-over-day change in volume by sector
Fetch the grouped daily OHLCV from Polygon.io for the three trading dates listed in cells A1, A2, and A3. Write each day's data into a separate tab named after the date. Then write a "Volume Trend" tab that shows each sector's total volume for each day and the day-over-day percentage change.
Three days of full-market data, sector aggregation, and volume trend — in one structured prompt.
Try It
Open a Google Sheet with a trading date in cell A1 and Get the 7-day free trial of SheetXAI. Ask it to fetch the full grouped daily OHLCV snapshot from Polygon.io and write it into a market snapshot tab ready for sector classification. For macro data to layer alongside equity performance, see the spoke on pulling Treasury yields and macro data. For the full partner overview, see the Polygon.io hub.