The Scenario
You run a 20-stock watchlist in a Google Sheet. Every morning before the open you want the current 14-day RSI and 20-day EMA for each ticker so you can make your entry and exit decisions without opening a charting platform. For the third week in a row you've been copying values by hand from your brokerage's screener, one ticker at a time, because you never had a better answer.
The bad version:
- You open a charting platform, search each ticker individually, note the RSI and EMA from the indicator panel, and type the values into your sheet — 20 repetitions, about four minutes each.
- Around ticker 12 you misread the EMA off a zoomed chart and write 187.40 instead of 197.40. You won't catch it until you flag a trade based on the wrong signal.
- The whole process takes 90 minutes every morning, which means by the time you're done, the first 10 values are already 90 minutes stale.
The constraint isn't time, exactly — it's that manual lookups at this frequency are incompatible with acting on what you find.
The Easy Way: One Prompt in SheetXAI
SheetXAI is an AI agent that lives inside your Google Sheet. It reads the ticker list, calls the Polygon.io technical indicators API for each one, and writes the values into the columns you specify — including conditional formatting if you want it.
For each ticker in column A, fetch the current 14-day RSI from Polygon.io and write the value into column B, highlighting any ticker with RSI below 30 in green and above 70 in red.
What You Get
- Column B: current 14-day RSI for each ticker, formatted to two decimal places.
- Green fill on rows where RSI is below 30 (oversold). Red fill on rows where RSI is above 70 (overbought).
- If a ticker returns no data — market not yet open, invalid symbol — the cell is left blank with a note rather than silently showing zero.
What If the Data Is Not Quite Ready
I also want MACD and signal line alongside RSI
For each ticker in column A, fetch the current 14-day RSI, MACD value, and MACD signal line from Polygon.io and write the RSI into column B, MACD value into column C, and signal line into column D.
The watchlist includes forex pairs and I need EMA for those too
For each ticker in column A — some are equities in standard format, others are forex pairs in C:EURUSD format — fetch the 20-day EMA from Polygon.io for each and write the value into column B. Handle both asset types.
Some tickers have been delisted and the API returns errors for them
For each ticker in column A, fetch the 14-day RSI from Polygon.io. If a ticker returns an error or no data, write "N/A — check symbol" into column B instead of leaving it blank. Then write all valid RSI values into column B as normal.
Pull RSI and EMA, flag divergence, and note tickers where RSI is falling while EMA is rising
For each ticker in column A, fetch the 14-day RSI and 20-day EMA from Polygon.io and write them into columns B and C. Then add a "Signal" column in D: if RSI is below 40 and EMA is trending upward (EMA today is greater than EMA 5 days ago), write "Divergence — watch". Otherwise leave column D blank.
The divergence logic and the data pull in one instruction. You describe what you want to see; SheetXAI handles the fetch and the conditional logic inline.
Try It
Open your watchlist Google Sheet and Get the 7-day free trial of SheetXAI. Ask it to pull RSI and EMA from Polygon.io for every ticker and apply your threshold formatting. For historical OHLC across your full portfolio, see the spoke on pulling historical OHLC data. For the complete partner overview, see the Polygon.io hub.